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Caffeine fading: Behavioral treatment of caffeine abuse
BEHAVIORTHERAPY16, 15-27 (1985)
Caffeine Fading: Behavioral Treatment of Caffeine Abuse JACK E. JAMES
The Flinders University of South Australia KERYN P. STIRLING B. A. MAY HAMPTON
University of Queensland Despite growing concern over the possible pathogenic effects of caffeine, relatively few systematic attempts have been made to assist chronic abusers to reduce intake to more moderate and safer levels. While previous studies have been based on observation of single subjects, the present investigation employed a factorial experimental design to examine the efficacy of caffeine fading among groups of high-caffeine users. Twenty-seven subjects were assigned to three equal-sizedgroups: self-initiatedtreatment, caffeine fading, and caffeine fading plus relaxation, Results confirmed the efficacy of caffeine fading (a treatment regimen involving a series of prescribed step-wise reductions in criterion rate of caffeine intake). However, no firm conclusions were permitted concerning possible further benefits arising from the addition of relaxation training.
Caffeine abuse m a y b e r e g a r d e d as t h e g e n e r i c t e r m for all f o r m s o f c h r o n i c o r h a b i t u a l use o f caffeine at l e v e l s w h i c h a r e p o t e n t i a l l y d a m a g i n g to h e a l t h ( J a m e s & Stifling, 1983). Caffeine a b u s e , t h e r e f o r e , s u b s u m e s the m o r e specific t e r m o f caffeinism w h i c h refers to s u s t a i n e d a b u s e in the p r e s e n c e o f d e l e t e r i o u s b e h a v i o r a l , p s y c h o p h y s i o l o g i c a l , a n d / o r affective m a n i f e s t a t i o n s c o n s i s t e n t w i t h t h e k n o w n p h a r m a c o l o g i c a l effects o f caffeine ( G r e d e n , 1974; R i t c h i e , 1975). H a b i t u a l d a i l y i n t a k e in excess o f 500 to 600 m g ( a p p r o x i m a t e l y 7 t o 9 c u p s o f t e a o r 4 to 7 c u p s o f coffee) is g e n e r a l l y r e g a r d e d as r e p r e s e n t i n g a s i g n i f i c a n t h e a l t h r i s k ( G r e d e n , F o n t a i n e , L u b e t s k y , & C h a m b e r l i n , 1978). A l t h o u g h figures o n usage p a t t e r n s r e m a i n i m p r e c i s e , it h a s b e e n e s t i m a t e d t h a t 20 t o 30% o f t h e i n h a b i t a n t s o f t h e U n i t e d S t a t e s a n d C a n a d a c o n s u m e m o r e t h a n 500 m g o f caffeine p e r d a y , a n d t h a t 10% m a n i f e s t s y m p t o m s o f c a f f e i n i s m ( G r e Requests for reprints should be sent to J. E. James, School of Social Sciences, The Hinders University of South Australia, Bedford Park, S.A. 5042 Australia. 15 0005-7894/85/00154102751.00/0 Copyright1985by Associationfor Advancementof BehaviorTherapy Allrightsof reproductionin any formreserved.
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den et al., 1978; Kaplan and Shadock, 1981). Indeed, recent recognition of the problem of caffeinism has led to its being included as a separate classification in the Diagnostic and Statistical Manual of Mental Disorders (3rd ed.) of the American Psychiatric Association (1980). The symptoms of caffeinism include restlessness, anxiety, irritability, agitation, muscle tremor, insomnia, headache, diuresis, sensory disturbances (e.g., tinnitus), cardiovascular symptoms (e.g., tachycardia, arrhythmias), and gastrointestinal complaints (e.g., nausea, vomiting, diarrhea) (Victor, Lubetsky, & Greden, 1981). Moreover, habitual caffeine use, with or without symptoms ofcaffeinism in evidence, has been related to the development of a variety of disease states, including cardiovascular disease (Dawber, Kannel, & Gordon, 1974; Thelle, Arnesen, & Forde, 1983), pancreatic cancer (MacMahon, Yen, Trichopoulos, Warren, & Nardi, 1981), diabetes (Cheraskin & Ringsdorf, 1968), and problems of fetal development and obstetric difficulties in pregnant women (Weathersbee, Olsen, & Lodge, 1977). Although evidence of caffeine as an etiological factor in the development of specific disease states remains largely suggestive rather than definitive (James & Stifling, 1983), increasing concern is being expressed over the possible pathogenic effects of the drug (e.g., Sawyer, Julia, & Turin, 1982; Thelle et al., 1983). Part of this concern stems from the ubiquitous presence of caffeine in the diets of diverse peoples throughout the world. In addition to the widely consumed beverages of tea and coffee, caffeine is present in cola-based soft drinks, chocolate, and an array of prescription and nonprescription medications, including over-the-counter analgesics and cold preparations (Bunker & McWilliam, 1979; Sawyer et al., 1982). Despite growing concern, relatively little has yet been done t,J assist chronic abusers to reduce caffeine consumption. To date, the only systematic attempts to effect reductions in caffeine intake all appear to have been based on behavioral principles. In the first of these studies, Foxx and Rubinoff (1979) obtained promising results with three subjects who each reported substantial reductions in caffeine consumption during treatment, and these improvements were largely maintained at a 40-month follow-up (Foxx, 1982). The study employed a single-subject "changing criterion" design (Hartmann & Hall, 1976) in which treatment paralleled the nicotine and cigarette fading procedures used by Foxx and Brown (1979) and Foxx and Axelroth (1983) in the treatment of cigarette smoking. The principal strategy in these "fading" programs has been to combine self-monitoring with a series of predetermined step-wise reductions in the criterion rate of the target behavior (e.g., daily caffeine consumption, nicotine intake, cigarettes smoked) in the direction of a specified terminal goal (e.g., abstinence, or a moderate and presumably safer rate of consumption). Subsequently, Bernard, Dennehy, and Keefauver (1981) also reported positive results for a single subject in a study which employed caffeine fading procedures similar to those described by Foxx and Rubinoff (1979). A somewhat different approach was adapted by Hyner (1979) who used relaxation as the principal treatment to effect reductions in smoking
CAFFEINE ABUSE
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and caffeine intake in a single subject. However, the rationale for using relaxation was not given, and although reductions in caffeine use (and smoking) were reported, the design of the study precludes the observed benefits being attributed specifically to the influence of relaxation training. Notwithstanding the positive findings of the three relevant studies reported to date, the fact that all three investigated the behavior of single subjects (yielding a combined total of five subjects) poses a question concerning the generality of the findings. In addition, while the two studies which employed caffeine fading found the strategy to be effective (Bernard et al., 1981; Foxx & Rubinoff, 1979), both studies employed the procedure in the form of a multicomponent treatment "package." As such, it is unclear which of treatment components were primarily responsible for effecting the observed reductions in caffeine consumption. In particular, it is unclear to what extent observed effects were due to the combined influence of self-monitoring and terminal goal-setting, as distinct from the principal additional element of caffeine fading, namely, the inclusion of a series of graduated intermediate goals specifying permitted maximum daily caffeine intake. Furthermore, the rationale for the use of fading procedures in the context of addictive behaviors derives in part from recognition that distressing withdrawal symptoms frequently accompany sudden marked reductions in the use of addictive drugs such as nicotine, alcohol, and caffeine. It is assumed that graduated withdrawal, typified by the use of fading procedures, serves to moderate withdrawal distress. However, the question arises whether withdrawal distress is indeed lessened, and whether any benefits might be derived from the use of adjunctive procedures designed to minimize particular drug-specific withdrawal symptoms. Two of the more frequent and aversive symptoms of caffeine withdrawal are headache and anxiety (Greden, 1974; Victor et al., 1981). Of the range of psychological treatments that have been used to manage these two symptom constellations, relaxation has figured prominently in the treatment of both (e.g., Hillenberg & Collins, 1982). It follows, then, that training in relaxation skills might be useful in facilitating attempts to reduce caffeine consumption. Thus, the present investigation had three major aims: (a) to employ a factorial experimental design rather than a single-subject methodology to examine the efficacy of caffeine fading among groups of high caffeine users; (b) to undertake a components analysis designed to evaluate the specific contribution of prescribed step-wise reductions in criterion rate of caffeine intake to the overall success of caffeine fading; (c) to evaluate the benefits, if any, to be gained by combining training in relaxation with caffeine fading.
METHOD
Subjects Subjects were selected from 120 respondents to public media exposure which asked for volunteers to participate in a study designed to reduce
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excessive caffeine consumption. The major selection criteria were: (a) the consumption of at least eight cups of tea or coffee per day; (b) a history of sustained caffeine abuse, which for most subjects included experiencing one or more symptoms characteristic of caffeinism; (c) preparedness to participate in a protracted intervention involving detailed self-monitoring of specified behaviors; and (d) the availability of a person in the volunteer's natural environment willing to provide an independent assessment of the subject's caffeine intake. Twenty-seven subjects (25 women and 2 men) were admitted into the study. The mean age was 35.5 years, and the range was 22 to 56 years. Overall, the subjects exhibited higher levels of caffeine abuse than subjects described in previous treatment studies. For example, the three subjects in the Foxx and Rubinoff (1979) study each consumed an average of less than 1,200 mg of caffeine per day prior to treatment, while the mean baseline rate for subjects in the present study was found to be 1,663 mg per day, with a range of 744 to 4,500 mg per day. This quantity of the drug was consumed in a mean of 18 cups of tea or coffee per day, with a range of 8 to 36 cups daily.
Procedure Subjects met individually with a therapist (the second author) on five occasions spanning three experimental phases: baseline, treatment, and follow-up. Baseline. At the first meeting, subjects were provided with instructions and materials designed to enable them to self-monitor daily rate and pattern of caffeine consumption. Prepared sheets were provided on which subjects recorded the time, setting, activity, and others present for each cup of tea and coffee they consumed. These reports were used by the experimenters to calculate daily caffeine intake. The conversion rates used were those reported by Foxx and Rubinoff (1979), which in turn were derived from fgures reported by Greden (1974). That is, brewed coffee was estimated to contain 125 mg of caffeine per cup, instant coffee 93 mg per cup, and tea 68 mg per cup. Of the 14 self-monitoring sheets which were supplied at the first meeting, 7 were returned by mail to the therapist after 1 week, while the remainder were brought to the next meeting with the therapist scheduled for 2 weeks following the first. The second meeting with the therapist constituted the end of baseline. Prior to this meeting, subjects were matched in groups of three on the basis of their daily caffeine intake as evidenced by their first 7 days of baseline recordings, and the members of each matched triplet were then assigned at random to one of three treatment conditions. During the second meeting, treatment details were presented and materials provided to enable subjects to implement their assigned treatment regimen. Three additional measures were introduced at the second meeting. Subjects completed the Self-Motivation Inventory (SMI) devised by Dishman and Ickes (198 l) as a measure of persistence in implementing self-regulated behavior change. In addition, they completed a set of four 8-point scales designed to measure level of therapeutic expectancies. This Expec-
CAFFEINE ABUSE
19
tancy Scale (ES) was derived from measures described by Borkovec and Nau (1972) and was designed to provide an indication of the relative credibility of the three respective treatment conditions. Finally, since treatment was to be focused on the consumption of tea and coffee, it was anticipated that subjects might compensate for reduction in caffeine intake from these sources by increasing (wittingly or otherwise) their intake of other available caffeine-containing substances. The theoretical support for this expectation derives from the "'set-point" model of addictive behavior which postulates that smokers, for example, regulate their rate of smoking to maintain a stable level of nicotine in the blood (Schachter, 1977, 1978). Hence, all subjects were provided with an Other Substances Inventory (OSI) on which they recorded changes in consumption levels of common caffeine-containing foods other than tea and coffee (e.g., chocolate, cola drinks). Multiple copies of the OSI were provided, and subjects completed a separate inventory for each of the 4 weeks of treatment. Treatment. The second meeting signaled the beginning of the treatment phase and was concluded with an appointment being made for a third meeting with the therapist scheduled for 4 weeks hence. Subjects were instructed to continue the self-monitoring activities outlined above (in addition to the treatment procedures to be described below) throughout the ensuing 4-week period. They were required to return 14 completed self-monitoring sheets by mail to the therapist at the midway point of treatment and to return the remaining 14 sheets in person at their next (third) appointment. A common component of the three treatment conditions was that all subjects were given the goal of reducing caffeine consumption to five cups per day by the 4th week of treatment. This goal was selected because it is believed to represent a relatively safe level of consumption (Foxx & Rubinoff, 1979; Greden, 1974). The respective treatment conditions were self-initiated treatment, caffeine fading, and caffeine fading plus relaxation. In view of recent findings reported by James and Hampton (1982), particular care was taken not to vary the degree of therapist direction given to subjects in relation to treatment elements common to all three conditions. In addition, every effort was made to maintain a common session length across conditions. While this goal was generally achieved, subjects given relaxation training at the second meeting actually received 15 to 20 min extra therapist attention at that meeting (additional to the 60 min received by subjects in the other two conditions). In the self-initiated (SI) condition subjects were provided with printed information describing the symptomatology ofcaffeinism (e.g., headache, insomnia, "'coffee nerves") and illnesses possibly associated with habitual caffeine use (e.g., gastrointestinal disorders, cardiovascular disease, problems of fetal development). In addition, printed information was provided on ways to control urges to consume caffeine (e.g., use of substitute beverages, arranging competing activities, reminding oneself of the possible deleterious consequences of continued use). SI subjects were also provided with the Caffeine Reduction Chart which was used to graph their daily
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JAMES, STIRLING, AND H A M P T O N
caffeine consumption, and they were told that the terminal goal of treatment was five cups or less per day. This goal was indicated by entering a "five-cups-a-day" goal line on SI subjects' Caffeine Reduction Charts at the 4th week. That is, the SI condition omitted any reference to a weekby-week progressively diminishing (i.e., fading) criterion of caffeine consumption. Subjects were merely instructed to continue to self-monitor and to use the information provided on ways to control urges as part of their effort to attain the goal of five cups per day or less by the 4th week of treatment. As such, the SI condition served as an active treatment control for the two caffeine fading conditions described below. Caffeine fading (C10 subjects received the same printed material (detailing the hazards of excessive caffeine consumption and hints on how to control urges) as was given to SI subjects. For CF subjects, however, in addition to the terminal goal of five cups per day being shown on their Caffeine Reduction Charts a specific weekly changing criterion was also shown. That is, the Caffeine Reduction Chart for CF subj~cts showed a specific caffeine intake goal for each week which was individually determined to represent four diminishing steps of equivalent size leading to the goal of five cups per day. For example, a subject whose consumption rate was 25 per day during the first week of baseline was asked to consume no more than 20, 15, 10, and 5 cups per day for each of the respective 4 weeks of treatment. Subjects in the third condition, caffeine fading plus relaxation (CFR), received the same treatment as CF subjects with the addition of relaxation training in the form of an abridged version of Jacobson's method (Wolpe, 1969). CFR subjects received one 40-rain session of progressive muscle relaxation from the therapist in person during their second meeting, and the session concluded with their being given a tape of recorded relaxation instructions to take home. They were directed to listen to the taped instructions daily, and to record their daily relaxation practice. However, in contrast to the unambiguous requirement that all participating subjects maintain up-to-date caffeine-intake forms as a continuing condition of treatment, no particular contingencies were specified in relation to the additional request that CFR subjects self-monitor their assigned daily relaxation practice. The unfortunate consequence of this omission was that the relaxation records for several subjects were incomplete and thereby precluded a systematic analysis of the extent to which the CFR group actually complied with the instruction to practice daily. Follow-up. Follow-up sessions were conducted at 6 and 18 weeks following the termination of treatment. Subjects were contacted by telephone and mail prior to each follow-up session, and asked to reinstate the selfmonitoring procedures they had followed during the baseline and treatment phases of the study. On both occasions, they were asked to selfmonitor for 7 days preceding each scheduled meeting and to bring their completed self-monitoring sheets to the session. Reliability. Certain reservations must always pertain in relation to data derived from the subjects' self-observations, particularly when these are
CAFFEINE ABUSE
21
obtained in naturalistic settings which provide little opportunity for controlled surveillance. The use of independent observers has provided a partial solution to the problem in other areas such as smoking cessation (e.g., Lichtenstein & Danaher, 1976) and alcohol abuse (e.g., Caddy & Lovibond, 1976). With regard to the treatment of caffeine abuse, Foxx and Rubinoff(1979) asked independent observers to report whether they had noticed any "gross" changes in individual subject's rates of coffee drinking, but no quantitative data were obtained. Bernard et al. (1981) obtained similar "subjective evaluations" from an independent observer during the treatment phase of their study, but subsequently they were able to obtain quantitative data at follow-up which indicated a satisfactory level of interobserver agreement for that phase of the study. In the present investigation, each subject was required to arrange for an individual with whom they had regular contact (usually a member of the family but in some instances a friend or neighbor) to provide independent observations of the subject's tea and coffee consumption. The independent observers were each required to make themselves available for at least one continuous 3-hour period of observation per week throughout the 6 weeks covering the baseline and treatment phases of the investigation. The observer's task was to record the subject's tea and coffee intake on prepared sheets which exactly paralleled the subject's self-monitoring sheets. Level of agreement was calculated by expressing number of agreements as a percentage of agreements plus disagreements. Although the possibility of collusion between subjects and observers cannot be ruled out, a high level of agreement (92%) was reported.
RESULTS Caffeine lntake Two-way ANOVA with repeated measures on one factor indicated a highly significant reduction in caffeine intake over time (F(7, 168) - 30.29, p < .001). While the overall main effect for groups did not reach significance (F(2, 24) = 2.68, p > .05), a significant Group x Time interaction (F(14, 168) = 1.86, p < .05) indicated significant group divergence during one or more phases of the study. With regard to the baseline phase, a two-way ANOVA indicated no significant change in mean caffeine intake (F(1, 24) = 1.15, p > .05), no significant difference between groups (F(2, 24) < 1), and no significant interaction (F(2, 24) < 1) during the 2week baseline period. However, a similar analysis revealed a different pattern of results for the treatment phase. Subjects reported a significant reduction in caffeine intake during the 4 weeks of treatment (F(3, 72) = 20.65, p < .001), and although there was no significant interaction effect (F(6, 7 2 ) < 1), there was a significant difference between groups (F(2, 24) = 4.86, p < .05). Moreover, this overall difference between groups was maintained at 6- and 18-weeks follow-up (Weeks 12 and 24) as indicated by a significant difference between groups (F(2, 24) = 9.23, p < .01). There was, however, no significant main effect for time (F(1, 24) <
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JAMES, STIRLING, AND HAMPTON 2000
BASELINE
TREATMENT
FOLLOW-UP
A
e-.-e CF
16oo
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CFR
1200
800
ill U,. U,.
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400
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4 5 WEEKS
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FIG. I. Daily caffeine intake (in rags) during baseline, treatment, and follow-up phases for self-initiated treatment (SI), caffeine fading (CF), and caffeine fading plus relaxation
(CFR). 1) during the follow-up period, and no significant interaction effect (F(I, 24) < 1). This general pattern of results is illustrated in Fig. 1 where it can be seen that, in contrast to a relatively stable baseline, the three groups evidenced progressive reductions in caffeine intake during the 4 weeks of treatment, and it is apparent that these improvements were substantially maintained at follow-up. It is evident from the above analysis that the group divergence indicated by the significant overall Time x Group interaction arose during the treatment phase. Fig. 1 suggests that this divergence between groups became more pronounced as treatment progressed, and this impression was confirmed by a one-way ANOVA of caffeine intake scores conducted for each of the 4 weeks of treatment (Weeks 3 through 6). During the first 2 weeks of treatment there were no significant between-group differences (F(2, 24) < 1 and F(2, 24) = 2.95, p > .05 for Weeks 3 and 4, respectively). However, by the 3rd week of treatment (Week 5) the difference between groups was significant (F(2, 2 4 ) = 7.31, p < .01), and this difference became more pronounced by the 4th and last week of treatment (F(2, 24) -- 17.09, p < .001). The Newman-Keuls test was used to examine the significance of pairwise differences between the three groups at the end of treatment. While both caffeine fading groups reported significantly lower levels of caffeine use at Week 6 than the SI group (p < .01), CF and CFR subjects did not differ significantly from one another (p > .05). Moreover, the same pattern of results was maintained when subjects were subsequently assessed at 6- and 18-weeks follow-up. In addition to these differences in the efficacy of the three treatment conditions, comparisons between subjects' baseline levels of caffeine intake and their intake levels at the end of
CAFFEINE ABUSE
23
treatment indicated significant reductions for all three groups (/7 < .01). Conversely, there were no significant differences with regard to subjects' caffeine intake at the end of treatment and their subsequent use of the drug at 6- and 18-weeks follow-up for any of the three groups (17 > .05). Finally, informal inspection of data appeared to confirm the clinical significance of certain of the statistically significant findings reported above. In particular, it can be seen from Fig. 1 that by the end of treatment CFR subjects succeeded in reducing mean daily consumption to less than 500 mg, and that their reported intake at Weeks 12 and 14 remained below that figure. By comparison, intake levels for CF and SI subjects during the same period remained above 700 and 1,000 mg of caffeine per day, respectively. With regard to the specified terminal goal of no more than five cups of tea or coffee per day, one SI and four CF subjects were successful, whereas seven subjects in the CFR group met criterion (while the remaining two subjects reported six cups per day).
Expectancy Scale Overall ES scores indicated that irrespective of the treatment condition to which they were assigned, subjects expressed high positive expectancies concerning the potential efficacy of the treatment they were to receive. A mean rating of six was recorded for each of the four 8-point scales, and there were no significant differences in total ES scores between the three groups (F(1, 24) < d). Thus, despite actual differences in treatment method and efficacy, it appears from subjects' expressed beliefs and expectations that all three conditions were equally credible.
Other Substances Inventory The size and significance of the reductions in caffeine use reported by subjects in the present study lend credibility to the hypothesis that caffeine deprivation might result in compensatory increases in consumption of other caffeine-containing substances. However, one-way ANOVAs for repeated measures indicated no significant changes prior to, during, or after treatment in subjects" reported usage of the caffeine-containing substances surveyed by the OSI. That is, contrary to what might be expected on the basis of set-point theory, subjects did not appear to compensate for reduced caffeine intake from tea and coffee by increasing consumption of alternative sources of caffeine.
Self-Motivation Inventory There were no differences between groups with regard to SMI scores obtained at Week 2 (F(2, 24) < 1). SMI scores correlated with caffeine intake at Week 6 in the anticipated direction (i.e., a higher SMI score being associated with a lower level of caffeine intake), but the association was not significant (r = - . 3 0 , p > .05). However, this result should not be viewed as an adequate test of the predictive validity of the SMI. The low correlation may be explained in relation to the apparent "floor" effect which resulted from many subjects reaching the treatment criterion of
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JAMES, STIRLING, AND HAMPTON
five cups per day. That is, the apparent overall success of treatment mitigated against the identification of factors which, given a more variable treatment outcome, might have better predicted level of treatment success.
DISCUSSION In view of the significant and lasting reductions in caffeine intake observed in the present study, it may be concluded that the caffeine fading procedure served as an effective intervention for chronic caffeine abuse. As such, present results broaden the base of empirical support provided by earlier single-subject investigations (Bernard et al., 1981; Foxx & Rubinoff, 1979). In addition, the superiority of the two caffeine-fading conditions (CF and CFR) over the SI condition (in which a single terminal goal was specified) confirms that a critical feature contributing to the efficacy of caffeine fading is the inclusion of progressively diminishing intermediate goals. In this respect, present results are consistent with those of Bandura and Simon (1977) who found relatively small immediate goals to be more effective than larger delayed ones in modifying the eating behavior of obese subjects. Despite the relative inferiority of the SI condition, it is interesting that following a stable baseline of caffeine abuse, SI subjects also evidenced moderate though significant reductions in consumption during the 4-week treatment phase. In the absence of a no-treatment control condition, it is not possible to gauge the precise significance of SI subjects' reductions in caffeine consumption. However, the apparent response of these subjects to a relatively nondirective intervention, consisting of daily self-monitoring, terminal goal setting, advice on how to control urges to consume caffeine, and information on the possible untoward consequences of continued abuse, augurs well for possible future larger scale programs. A media campaign, for example, which might need to forgo individual tailoring because of difficulties in arranging one-to-one contact with the target population, could nevertheless be expected to achieve at least moderate success in view of the performance of SI subjects in the present study. Even modest reductions in caffeine use, when considered in the context of patterns of population usage might ultimately be found to have profound implications for the health of the community. The failure of CFR subjects to achieve significantly lower levels of caffeine intake than CF subjects is unfortunately a somewhat equivocal result. On one hand, this finding could indicate that withdrawal distress either did not undermine the efficacy of caffeine fading for CF subjects, or that withdrawal symptoms were not alleviated by relaxation training and therefore resulted in no significant additional benefits for CFR subjects. On the other hand, this relatively straightforward interpretation of the results is complicated by several confounding factors which deserve attention. To begin with, there are grounds for questioning the adequacy of the relaxation training received by CFR subjects, consisting as it did of a single session with the therapist plus tape-recorded instructions. For example, Lehrer (1982), in a recent review of the relaxation literature
CAFFEINE ABUSE
25
concluded that "tape-recorded instruction appears to be completely ineffective as a m e t h o d for teaching relaxation as a skill that can be used across situations" (p. 417). In addition, although in interview C F R subjects generally reported substantial compliance with the instruction to practice regularly, the absence o f systematic data on the frequency with which the group actually practiced is a weakness o f the study. Similarly, despite the fact that in interview subjects generally reported relatively little withdrawal distress, the absence o f systematic data on withdrawal symptoms is also a weakness. The low frequency o f reported withdrawal symptoms, if reliable, would suggest the u n i m p o r t a n c e o f providing adjunctive treatment such as relaxation training, at least so far as such training is undertaken for the purpose o f facilitating treatment compliance by reducing withdrawal distress. However, it is clear that future caffeine reduction studies should attempt to systematically m o n i t o r the course and degree o f subjects' withdrawal distress. Finally, notwithstanding the failure o f relaxation training to significantly improve the efficacy o f caffeine fading, there was a noticeable trend in the direction o f greater success among C F R subjects. Indeed, the presence of a possible " f l o o r " effect created by the relatively large proportion o f subjects who reached the treatment goal o f five or less cups per day m a y have precluded a significant result being obtained in support o f the addition o f relaxation training to caffeine fading. Considering this and the other reservations m e n t i o n e d above, the therapeutic benefits o f relaxation training for persons following a regimen o f caffeine reduction must be regarded an open question. In summary, then, the present study provides relatively unequivocal support for caffeine fading as a reliable means to effect significant reductions in caffeine use, at least amongst m o t i v a t e d subjects. However, no firm conclusions are warranted concerning the possible additional benefits to be gained from a c o m b i n e d relaxation training/caffeine fading procedure, as distinct from caffeine fading alone.
REFERENCES American Psychiatric Association. Diagnostic and statistical manual of mental disorders (3rd ed.). (1980). Washington, DC: Author. Bandura, A., & Simon, K. M. (1977). The role of proximal intentions in self-regulation of refractory behavior. Cognitive Therapy and Research, 1, 177-193. Bernard, M. E., Dennehy, S., & Keefauver, L.W. (1981). Behavioral treatment of excessive coffee and tea drinking: A case study and partial replication. Behavior Therapy, 12, 543-548. Borkovec,T. D., & Nau, S. D. (1972). Credibility of analogue treatment rationales. Journal of Behavior Therapy and Experimental Psychiatry, 1, 257-260. Bunker, M. I., & McWilliam, M. (1979). Caffeinecontent of common beverages. Journal of Dietetics Association, 74, 28-32. Caddy, G. R., & Lovibond, S. H. (1976). Self-regulationand discriminated aversive conditioning in the modification of alcoholics' drinking behavior. Behavior Therapy, 7, 223-230. Cheraskin, E., & Ringsdorf, W. M., Jr. 0968). Blood-glucoselevels after caffeine.Lancet, 1, 689.
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Dawber, T. R., Kannel, Q. B., & Gordon, T. (1974). Coffee and cardiovascular disease. Observations from the Framingham Study. New England Journal of Medicine, 291, 871-874. Dishman, R. K., & Ickes, W. (1981). Self-motivation and adherence to therapeutic exercise. Journal of Behavioral Medicine, 4, 421-438. Foxx, R. M. (1982). Behavioral treatment of caffeinism: A 40-month follow-up, the Behavior Therapist, 5, 23-24. Foxx, R. M., & Axelroth, E. (1983). Nicotine fading, self-monitoring and cigarette .'ading to produce cigarette abstinence or controlled smoking. Behaviour Research and Therapy, 21, 17-27. Foxx, R. M., & Brown, R. A. (1979). Nicotine fading and self-monitoring for cigarette abstinence or controlled smoking. Journal of Applied Behavior Analysis, 2, 111-125. Foxx, R.M.,&Rubinoff, A. (1979). Behavioral treatment ofcaffeinism: Reducing excessive coffee drinking. Journal of Applied Behavior Analysis, 12, 344-355. G~-'den, J. F. (1974). Anxiety or caffeinism: A diagnostic dilemma. American Journal of Psychiatry, 131, 1089-1092. Greden, J. F., Fontaine, P., Lubetsky, M., & Chamberlin, K. (1978). Anxiety and depression associated with caffeinism among psychiatric patients. American Journal of Psychiatry, 135, 963-966. Hartmann, D. P., & Hall, R.V. (1976). The changing criterion design. Journal of Applied Behavior Analysis, 9, 527-532. Hillenberg, J. B., & Collins, R. L. (1982). A procedural analysis and review of relaxation training research. Behaviour Research and Therapy, 20, 251-260. Hyner, G.C. (1979). Relaxation as principal treatment for excessive cigarette and caffeine ingestion by a college female. Psychological Reports, 45, 531-534. James, J. E., & Hampton, B. A. M. (1982). The relative efficacy of directive and nondirective treatment in behavioral weight control. Behavior Therapy, 12, 463-475. James, J. E., & Stifling, K.P. (1983). Caffeine: A survey of some of the known and suspected deleterious effects of habitual use. British Journal of Addiction, 78, 251-258. Kaplan, J. I., & Shadock, B. J. (1981). Modern synopsis of comprehensive textbook of psychiatry~Ill (3rd ed.). Baltimore: Williams and Wilkins. Keppel, G. (1973). Design and analysis: A researcher's handbook. Englewood Cliffs, NJ: Prentice-Hall. Lehrer, P. M. (1982). How to relax and how not to relax: A re-evaluation of the work of Edmund Jacobson--I. Behaviour Research and Therapy, 20, 417-428. Lichtenstein, E., & Danaher, B, G. (1976). Modification of smoking behavior: A critical analysis of theory, research and practice. In M. Hersen, R. M. Eisler, & P. M. Miller (Eds.), Progress in behavior modification (pp. 79-132). New York: Academic. MacMahon, B., Yen, S., Trichopoulos, D., Warren, K., & Nardi, G. (1981). Coffee and cancer of the pancreas. New England Journal of Medicine, 304, 630--633. Ritchie, J. M. (1975). The xanthines. In L. S. Goodman & A. Gilman (Eds.), Pharmacological basis of therapeutics (pp. 367-376). New York: Macmillan. Sawyer, D. A., Julia, H. L., & Turin, A. C. (1982). Caffeine and human behavior: Arousal, anxiety, and performance effects. Journal of Behavioral Medicine, 5, 415-439. Schachter, S. (1977). Nicotine regulation in heavy and light smokers. Journal of Experimental Psychology: General, 106, 5-12. Schachter, S. (1978). Pharmacologfical and psycholog~cal determinants of smoking. Annals of lnternal Medicine, 88, 104--114. Thelle, D. S., Arnesen, E., & Forde, O. H. (1983). The Tromso heart study: Does coffee raise serum cholesterol? New England Journal of Medicine, 308, 1454-1457.
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Victor, B. S., Lubetsky, M., & Greden, J. F. (1981). Somatic manifestations ofcaffeinism.
Journal of Clinical Psychiatry, 42, 185-188. Weathersbe¢, P. S., Olsen, C. K., & Lodge, J. R. (1977). Caffeine and pregnancy: A retrospective study. Postgraduate Medicine, 62, 64-69. Wolpe, J. (1969). The practice of behavior therapy. New York: Pergamon. RECEIVED: February 27, 1984
FINAL ACCEPTANCE:July 11, 1984
Caffeine Fading: Behavioral Treatment of Caffeine Abuse JACK E. JAMES
The Flinders University of South Australia KERYN P. STIRLING B. A. MAY HAMPTON
University of Queensland Despite growing concern over the possible pathogenic effects of caffeine, relatively few systematic attempts have been made to assist chronic abusers to reduce intake to more moderate and safer levels. While previous studies have been based on observation of single subjects, the present investigation employed a factorial experimental design to examine the efficacy of caffeine fading among groups of high-caffeine users. Twenty-seven subjects were assigned to three equal-sizedgroups: self-initiatedtreatment, caffeine fading, and caffeine fading plus relaxation, Results confirmed the efficacy of caffeine fading (a treatment regimen involving a series of prescribed step-wise reductions in criterion rate of caffeine intake). However, no firm conclusions were permitted concerning possible further benefits arising from the addition of relaxation training.
Caffeine abuse m a y b e r e g a r d e d as t h e g e n e r i c t e r m for all f o r m s o f c h r o n i c o r h a b i t u a l use o f caffeine at l e v e l s w h i c h a r e p o t e n t i a l l y d a m a g i n g to h e a l t h ( J a m e s & Stifling, 1983). Caffeine a b u s e , t h e r e f o r e , s u b s u m e s the m o r e specific t e r m o f caffeinism w h i c h refers to s u s t a i n e d a b u s e in the p r e s e n c e o f d e l e t e r i o u s b e h a v i o r a l , p s y c h o p h y s i o l o g i c a l , a n d / o r affective m a n i f e s t a t i o n s c o n s i s t e n t w i t h t h e k n o w n p h a r m a c o l o g i c a l effects o f caffeine ( G r e d e n , 1974; R i t c h i e , 1975). H a b i t u a l d a i l y i n t a k e in excess o f 500 to 600 m g ( a p p r o x i m a t e l y 7 t o 9 c u p s o f t e a o r 4 to 7 c u p s o f coffee) is g e n e r a l l y r e g a r d e d as r e p r e s e n t i n g a s i g n i f i c a n t h e a l t h r i s k ( G r e d e n , F o n t a i n e , L u b e t s k y , & C h a m b e r l i n , 1978). A l t h o u g h figures o n usage p a t t e r n s r e m a i n i m p r e c i s e , it h a s b e e n e s t i m a t e d t h a t 20 t o 30% o f t h e i n h a b i t a n t s o f t h e U n i t e d S t a t e s a n d C a n a d a c o n s u m e m o r e t h a n 500 m g o f caffeine p e r d a y , a n d t h a t 10% m a n i f e s t s y m p t o m s o f c a f f e i n i s m ( G r e Requests for reprints should be sent to J. E. James, School of Social Sciences, The Hinders University of South Australia, Bedford Park, S.A. 5042 Australia. 15 0005-7894/85/00154102751.00/0 Copyright1985by Associationfor Advancementof BehaviorTherapy Allrightsof reproductionin any formreserved.
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JAMES, ST1RLING, AND HAMPTON
den et al., 1978; Kaplan and Shadock, 1981). Indeed, recent recognition of the problem of caffeinism has led to its being included as a separate classification in the Diagnostic and Statistical Manual of Mental Disorders (3rd ed.) of the American Psychiatric Association (1980). The symptoms of caffeinism include restlessness, anxiety, irritability, agitation, muscle tremor, insomnia, headache, diuresis, sensory disturbances (e.g., tinnitus), cardiovascular symptoms (e.g., tachycardia, arrhythmias), and gastrointestinal complaints (e.g., nausea, vomiting, diarrhea) (Victor, Lubetsky, & Greden, 1981). Moreover, habitual caffeine use, with or without symptoms ofcaffeinism in evidence, has been related to the development of a variety of disease states, including cardiovascular disease (Dawber, Kannel, & Gordon, 1974; Thelle, Arnesen, & Forde, 1983), pancreatic cancer (MacMahon, Yen, Trichopoulos, Warren, & Nardi, 1981), diabetes (Cheraskin & Ringsdorf, 1968), and problems of fetal development and obstetric difficulties in pregnant women (Weathersbee, Olsen, & Lodge, 1977). Although evidence of caffeine as an etiological factor in the development of specific disease states remains largely suggestive rather than definitive (James & Stifling, 1983), increasing concern is being expressed over the possible pathogenic effects of the drug (e.g., Sawyer, Julia, & Turin, 1982; Thelle et al., 1983). Part of this concern stems from the ubiquitous presence of caffeine in the diets of diverse peoples throughout the world. In addition to the widely consumed beverages of tea and coffee, caffeine is present in cola-based soft drinks, chocolate, and an array of prescription and nonprescription medications, including over-the-counter analgesics and cold preparations (Bunker & McWilliam, 1979; Sawyer et al., 1982). Despite growing concern, relatively little has yet been done t,J assist chronic abusers to reduce caffeine consumption. To date, the only systematic attempts to effect reductions in caffeine intake all appear to have been based on behavioral principles. In the first of these studies, Foxx and Rubinoff (1979) obtained promising results with three subjects who each reported substantial reductions in caffeine consumption during treatment, and these improvements were largely maintained at a 40-month follow-up (Foxx, 1982). The study employed a single-subject "changing criterion" design (Hartmann & Hall, 1976) in which treatment paralleled the nicotine and cigarette fading procedures used by Foxx and Brown (1979) and Foxx and Axelroth (1983) in the treatment of cigarette smoking. The principal strategy in these "fading" programs has been to combine self-monitoring with a series of predetermined step-wise reductions in the criterion rate of the target behavior (e.g., daily caffeine consumption, nicotine intake, cigarettes smoked) in the direction of a specified terminal goal (e.g., abstinence, or a moderate and presumably safer rate of consumption). Subsequently, Bernard, Dennehy, and Keefauver (1981) also reported positive results for a single subject in a study which employed caffeine fading procedures similar to those described by Foxx and Rubinoff (1979). A somewhat different approach was adapted by Hyner (1979) who used relaxation as the principal treatment to effect reductions in smoking
CAFFEINE ABUSE
17
and caffeine intake in a single subject. However, the rationale for using relaxation was not given, and although reductions in caffeine use (and smoking) were reported, the design of the study precludes the observed benefits being attributed specifically to the influence of relaxation training. Notwithstanding the positive findings of the three relevant studies reported to date, the fact that all three investigated the behavior of single subjects (yielding a combined total of five subjects) poses a question concerning the generality of the findings. In addition, while the two studies which employed caffeine fading found the strategy to be effective (Bernard et al., 1981; Foxx & Rubinoff, 1979), both studies employed the procedure in the form of a multicomponent treatment "package." As such, it is unclear which of treatment components were primarily responsible for effecting the observed reductions in caffeine consumption. In particular, it is unclear to what extent observed effects were due to the combined influence of self-monitoring and terminal goal-setting, as distinct from the principal additional element of caffeine fading, namely, the inclusion of a series of graduated intermediate goals specifying permitted maximum daily caffeine intake. Furthermore, the rationale for the use of fading procedures in the context of addictive behaviors derives in part from recognition that distressing withdrawal symptoms frequently accompany sudden marked reductions in the use of addictive drugs such as nicotine, alcohol, and caffeine. It is assumed that graduated withdrawal, typified by the use of fading procedures, serves to moderate withdrawal distress. However, the question arises whether withdrawal distress is indeed lessened, and whether any benefits might be derived from the use of adjunctive procedures designed to minimize particular drug-specific withdrawal symptoms. Two of the more frequent and aversive symptoms of caffeine withdrawal are headache and anxiety (Greden, 1974; Victor et al., 1981). Of the range of psychological treatments that have been used to manage these two symptom constellations, relaxation has figured prominently in the treatment of both (e.g., Hillenberg & Collins, 1982). It follows, then, that training in relaxation skills might be useful in facilitating attempts to reduce caffeine consumption. Thus, the present investigation had three major aims: (a) to employ a factorial experimental design rather than a single-subject methodology to examine the efficacy of caffeine fading among groups of high caffeine users; (b) to undertake a components analysis designed to evaluate the specific contribution of prescribed step-wise reductions in criterion rate of caffeine intake to the overall success of caffeine fading; (c) to evaluate the benefits, if any, to be gained by combining training in relaxation with caffeine fading.
METHOD
Subjects Subjects were selected from 120 respondents to public media exposure which asked for volunteers to participate in a study designed to reduce
18
JAMES, STIRLING, AND HAMPTON
excessive caffeine consumption. The major selection criteria were: (a) the consumption of at least eight cups of tea or coffee per day; (b) a history of sustained caffeine abuse, which for most subjects included experiencing one or more symptoms characteristic of caffeinism; (c) preparedness to participate in a protracted intervention involving detailed self-monitoring of specified behaviors; and (d) the availability of a person in the volunteer's natural environment willing to provide an independent assessment of the subject's caffeine intake. Twenty-seven subjects (25 women and 2 men) were admitted into the study. The mean age was 35.5 years, and the range was 22 to 56 years. Overall, the subjects exhibited higher levels of caffeine abuse than subjects described in previous treatment studies. For example, the three subjects in the Foxx and Rubinoff (1979) study each consumed an average of less than 1,200 mg of caffeine per day prior to treatment, while the mean baseline rate for subjects in the present study was found to be 1,663 mg per day, with a range of 744 to 4,500 mg per day. This quantity of the drug was consumed in a mean of 18 cups of tea or coffee per day, with a range of 8 to 36 cups daily.
Procedure Subjects met individually with a therapist (the second author) on five occasions spanning three experimental phases: baseline, treatment, and follow-up. Baseline. At the first meeting, subjects were provided with instructions and materials designed to enable them to self-monitor daily rate and pattern of caffeine consumption. Prepared sheets were provided on which subjects recorded the time, setting, activity, and others present for each cup of tea and coffee they consumed. These reports were used by the experimenters to calculate daily caffeine intake. The conversion rates used were those reported by Foxx and Rubinoff (1979), which in turn were derived from fgures reported by Greden (1974). That is, brewed coffee was estimated to contain 125 mg of caffeine per cup, instant coffee 93 mg per cup, and tea 68 mg per cup. Of the 14 self-monitoring sheets which were supplied at the first meeting, 7 were returned by mail to the therapist after 1 week, while the remainder were brought to the next meeting with the therapist scheduled for 2 weeks following the first. The second meeting with the therapist constituted the end of baseline. Prior to this meeting, subjects were matched in groups of three on the basis of their daily caffeine intake as evidenced by their first 7 days of baseline recordings, and the members of each matched triplet were then assigned at random to one of three treatment conditions. During the second meeting, treatment details were presented and materials provided to enable subjects to implement their assigned treatment regimen. Three additional measures were introduced at the second meeting. Subjects completed the Self-Motivation Inventory (SMI) devised by Dishman and Ickes (198 l) as a measure of persistence in implementing self-regulated behavior change. In addition, they completed a set of four 8-point scales designed to measure level of therapeutic expectancies. This Expec-
CAFFEINE ABUSE
19
tancy Scale (ES) was derived from measures described by Borkovec and Nau (1972) and was designed to provide an indication of the relative credibility of the three respective treatment conditions. Finally, since treatment was to be focused on the consumption of tea and coffee, it was anticipated that subjects might compensate for reduction in caffeine intake from these sources by increasing (wittingly or otherwise) their intake of other available caffeine-containing substances. The theoretical support for this expectation derives from the "'set-point" model of addictive behavior which postulates that smokers, for example, regulate their rate of smoking to maintain a stable level of nicotine in the blood (Schachter, 1977, 1978). Hence, all subjects were provided with an Other Substances Inventory (OSI) on which they recorded changes in consumption levels of common caffeine-containing foods other than tea and coffee (e.g., chocolate, cola drinks). Multiple copies of the OSI were provided, and subjects completed a separate inventory for each of the 4 weeks of treatment. Treatment. The second meeting signaled the beginning of the treatment phase and was concluded with an appointment being made for a third meeting with the therapist scheduled for 4 weeks hence. Subjects were instructed to continue the self-monitoring activities outlined above (in addition to the treatment procedures to be described below) throughout the ensuing 4-week period. They were required to return 14 completed self-monitoring sheets by mail to the therapist at the midway point of treatment and to return the remaining 14 sheets in person at their next (third) appointment. A common component of the three treatment conditions was that all subjects were given the goal of reducing caffeine consumption to five cups per day by the 4th week of treatment. This goal was selected because it is believed to represent a relatively safe level of consumption (Foxx & Rubinoff, 1979; Greden, 1974). The respective treatment conditions were self-initiated treatment, caffeine fading, and caffeine fading plus relaxation. In view of recent findings reported by James and Hampton (1982), particular care was taken not to vary the degree of therapist direction given to subjects in relation to treatment elements common to all three conditions. In addition, every effort was made to maintain a common session length across conditions. While this goal was generally achieved, subjects given relaxation training at the second meeting actually received 15 to 20 min extra therapist attention at that meeting (additional to the 60 min received by subjects in the other two conditions). In the self-initiated (SI) condition subjects were provided with printed information describing the symptomatology ofcaffeinism (e.g., headache, insomnia, "'coffee nerves") and illnesses possibly associated with habitual caffeine use (e.g., gastrointestinal disorders, cardiovascular disease, problems of fetal development). In addition, printed information was provided on ways to control urges to consume caffeine (e.g., use of substitute beverages, arranging competing activities, reminding oneself of the possible deleterious consequences of continued use). SI subjects were also provided with the Caffeine Reduction Chart which was used to graph their daily
20
JAMES, STIRLING, AND H A M P T O N
caffeine consumption, and they were told that the terminal goal of treatment was five cups or less per day. This goal was indicated by entering a "five-cups-a-day" goal line on SI subjects' Caffeine Reduction Charts at the 4th week. That is, the SI condition omitted any reference to a weekby-week progressively diminishing (i.e., fading) criterion of caffeine consumption. Subjects were merely instructed to continue to self-monitor and to use the information provided on ways to control urges as part of their effort to attain the goal of five cups per day or less by the 4th week of treatment. As such, the SI condition served as an active treatment control for the two caffeine fading conditions described below. Caffeine fading (C10 subjects received the same printed material (detailing the hazards of excessive caffeine consumption and hints on how to control urges) as was given to SI subjects. For CF subjects, however, in addition to the terminal goal of five cups per day being shown on their Caffeine Reduction Charts a specific weekly changing criterion was also shown. That is, the Caffeine Reduction Chart for CF subj~cts showed a specific caffeine intake goal for each week which was individually determined to represent four diminishing steps of equivalent size leading to the goal of five cups per day. For example, a subject whose consumption rate was 25 per day during the first week of baseline was asked to consume no more than 20, 15, 10, and 5 cups per day for each of the respective 4 weeks of treatment. Subjects in the third condition, caffeine fading plus relaxation (CFR), received the same treatment as CF subjects with the addition of relaxation training in the form of an abridged version of Jacobson's method (Wolpe, 1969). CFR subjects received one 40-rain session of progressive muscle relaxation from the therapist in person during their second meeting, and the session concluded with their being given a tape of recorded relaxation instructions to take home. They were directed to listen to the taped instructions daily, and to record their daily relaxation practice. However, in contrast to the unambiguous requirement that all participating subjects maintain up-to-date caffeine-intake forms as a continuing condition of treatment, no particular contingencies were specified in relation to the additional request that CFR subjects self-monitor their assigned daily relaxation practice. The unfortunate consequence of this omission was that the relaxation records for several subjects were incomplete and thereby precluded a systematic analysis of the extent to which the CFR group actually complied with the instruction to practice daily. Follow-up. Follow-up sessions were conducted at 6 and 18 weeks following the termination of treatment. Subjects were contacted by telephone and mail prior to each follow-up session, and asked to reinstate the selfmonitoring procedures they had followed during the baseline and treatment phases of the study. On both occasions, they were asked to selfmonitor for 7 days preceding each scheduled meeting and to bring their completed self-monitoring sheets to the session. Reliability. Certain reservations must always pertain in relation to data derived from the subjects' self-observations, particularly when these are
CAFFEINE ABUSE
21
obtained in naturalistic settings which provide little opportunity for controlled surveillance. The use of independent observers has provided a partial solution to the problem in other areas such as smoking cessation (e.g., Lichtenstein & Danaher, 1976) and alcohol abuse (e.g., Caddy & Lovibond, 1976). With regard to the treatment of caffeine abuse, Foxx and Rubinoff(1979) asked independent observers to report whether they had noticed any "gross" changes in individual subject's rates of coffee drinking, but no quantitative data were obtained. Bernard et al. (1981) obtained similar "subjective evaluations" from an independent observer during the treatment phase of their study, but subsequently they were able to obtain quantitative data at follow-up which indicated a satisfactory level of interobserver agreement for that phase of the study. In the present investigation, each subject was required to arrange for an individual with whom they had regular contact (usually a member of the family but in some instances a friend or neighbor) to provide independent observations of the subject's tea and coffee consumption. The independent observers were each required to make themselves available for at least one continuous 3-hour period of observation per week throughout the 6 weeks covering the baseline and treatment phases of the investigation. The observer's task was to record the subject's tea and coffee intake on prepared sheets which exactly paralleled the subject's self-monitoring sheets. Level of agreement was calculated by expressing number of agreements as a percentage of agreements plus disagreements. Although the possibility of collusion between subjects and observers cannot be ruled out, a high level of agreement (92%) was reported.
RESULTS Caffeine lntake Two-way ANOVA with repeated measures on one factor indicated a highly significant reduction in caffeine intake over time (F(7, 168) - 30.29, p < .001). While the overall main effect for groups did not reach significance (F(2, 24) = 2.68, p > .05), a significant Group x Time interaction (F(14, 168) = 1.86, p < .05) indicated significant group divergence during one or more phases of the study. With regard to the baseline phase, a two-way ANOVA indicated no significant change in mean caffeine intake (F(1, 24) = 1.15, p > .05), no significant difference between groups (F(2, 24) < 1), and no significant interaction (F(2, 24) < 1) during the 2week baseline period. However, a similar analysis revealed a different pattern of results for the treatment phase. Subjects reported a significant reduction in caffeine intake during the 4 weeks of treatment (F(3, 72) = 20.65, p < .001), and although there was no significant interaction effect (F(6, 7 2 ) < 1), there was a significant difference between groups (F(2, 24) = 4.86, p < .05). Moreover, this overall difference between groups was maintained at 6- and 18-weeks follow-up (Weeks 12 and 24) as indicated by a significant difference between groups (F(2, 24) = 9.23, p < .01). There was, however, no significant main effect for time (F(1, 24) <
22
JAMES, STIRLING, AND HAMPTON 2000
BASELINE
TREATMENT
FOLLOW-UP
A
e-.-e CF
16oo
I.-
W1
z_.
m-.--m
CFR
1200
800
ill U,. U,.
,,( u
400
,
,
,
I
2
3
,
,
4 5 WEEKS
,
.
.
6
12
24
FIG. I. Daily caffeine intake (in rags) during baseline, treatment, and follow-up phases for self-initiated treatment (SI), caffeine fading (CF), and caffeine fading plus relaxation
(CFR). 1) during the follow-up period, and no significant interaction effect (F(I, 24) < 1). This general pattern of results is illustrated in Fig. 1 where it can be seen that, in contrast to a relatively stable baseline, the three groups evidenced progressive reductions in caffeine intake during the 4 weeks of treatment, and it is apparent that these improvements were substantially maintained at follow-up. It is evident from the above analysis that the group divergence indicated by the significant overall Time x Group interaction arose during the treatment phase. Fig. 1 suggests that this divergence between groups became more pronounced as treatment progressed, and this impression was confirmed by a one-way ANOVA of caffeine intake scores conducted for each of the 4 weeks of treatment (Weeks 3 through 6). During the first 2 weeks of treatment there were no significant between-group differences (F(2, 24) < 1 and F(2, 24) = 2.95, p > .05 for Weeks 3 and 4, respectively). However, by the 3rd week of treatment (Week 5) the difference between groups was significant (F(2, 2 4 ) = 7.31, p < .01), and this difference became more pronounced by the 4th and last week of treatment (F(2, 24) -- 17.09, p < .001). The Newman-Keuls test was used to examine the significance of pairwise differences between the three groups at the end of treatment. While both caffeine fading groups reported significantly lower levels of caffeine use at Week 6 than the SI group (p < .01), CF and CFR subjects did not differ significantly from one another (p > .05). Moreover, the same pattern of results was maintained when subjects were subsequently assessed at 6- and 18-weeks follow-up. In addition to these differences in the efficacy of the three treatment conditions, comparisons between subjects' baseline levels of caffeine intake and their intake levels at the end of
CAFFEINE ABUSE
23
treatment indicated significant reductions for all three groups (/7 < .01). Conversely, there were no significant differences with regard to subjects' caffeine intake at the end of treatment and their subsequent use of the drug at 6- and 18-weeks follow-up for any of the three groups (17 > .05). Finally, informal inspection of data appeared to confirm the clinical significance of certain of the statistically significant findings reported above. In particular, it can be seen from Fig. 1 that by the end of treatment CFR subjects succeeded in reducing mean daily consumption to less than 500 mg, and that their reported intake at Weeks 12 and 14 remained below that figure. By comparison, intake levels for CF and SI subjects during the same period remained above 700 and 1,000 mg of caffeine per day, respectively. With regard to the specified terminal goal of no more than five cups of tea or coffee per day, one SI and four CF subjects were successful, whereas seven subjects in the CFR group met criterion (while the remaining two subjects reported six cups per day).
Expectancy Scale Overall ES scores indicated that irrespective of the treatment condition to which they were assigned, subjects expressed high positive expectancies concerning the potential efficacy of the treatment they were to receive. A mean rating of six was recorded for each of the four 8-point scales, and there were no significant differences in total ES scores between the three groups (F(1, 24) < d). Thus, despite actual differences in treatment method and efficacy, it appears from subjects' expressed beliefs and expectations that all three conditions were equally credible.
Other Substances Inventory The size and significance of the reductions in caffeine use reported by subjects in the present study lend credibility to the hypothesis that caffeine deprivation might result in compensatory increases in consumption of other caffeine-containing substances. However, one-way ANOVAs for repeated measures indicated no significant changes prior to, during, or after treatment in subjects" reported usage of the caffeine-containing substances surveyed by the OSI. That is, contrary to what might be expected on the basis of set-point theory, subjects did not appear to compensate for reduced caffeine intake from tea and coffee by increasing consumption of alternative sources of caffeine.
Self-Motivation Inventory There were no differences between groups with regard to SMI scores obtained at Week 2 (F(2, 24) < 1). SMI scores correlated with caffeine intake at Week 6 in the anticipated direction (i.e., a higher SMI score being associated with a lower level of caffeine intake), but the association was not significant (r = - . 3 0 , p > .05). However, this result should not be viewed as an adequate test of the predictive validity of the SMI. The low correlation may be explained in relation to the apparent "floor" effect which resulted from many subjects reaching the treatment criterion of
24
JAMES, STIRLING, AND HAMPTON
five cups per day. That is, the apparent overall success of treatment mitigated against the identification of factors which, given a more variable treatment outcome, might have better predicted level of treatment success.
DISCUSSION In view of the significant and lasting reductions in caffeine intake observed in the present study, it may be concluded that the caffeine fading procedure served as an effective intervention for chronic caffeine abuse. As such, present results broaden the base of empirical support provided by earlier single-subject investigations (Bernard et al., 1981; Foxx & Rubinoff, 1979). In addition, the superiority of the two caffeine-fading conditions (CF and CFR) over the SI condition (in which a single terminal goal was specified) confirms that a critical feature contributing to the efficacy of caffeine fading is the inclusion of progressively diminishing intermediate goals. In this respect, present results are consistent with those of Bandura and Simon (1977) who found relatively small immediate goals to be more effective than larger delayed ones in modifying the eating behavior of obese subjects. Despite the relative inferiority of the SI condition, it is interesting that following a stable baseline of caffeine abuse, SI subjects also evidenced moderate though significant reductions in consumption during the 4-week treatment phase. In the absence of a no-treatment control condition, it is not possible to gauge the precise significance of SI subjects' reductions in caffeine consumption. However, the apparent response of these subjects to a relatively nondirective intervention, consisting of daily self-monitoring, terminal goal setting, advice on how to control urges to consume caffeine, and information on the possible untoward consequences of continued abuse, augurs well for possible future larger scale programs. A media campaign, for example, which might need to forgo individual tailoring because of difficulties in arranging one-to-one contact with the target population, could nevertheless be expected to achieve at least moderate success in view of the performance of SI subjects in the present study. Even modest reductions in caffeine use, when considered in the context of patterns of population usage might ultimately be found to have profound implications for the health of the community. The failure of CFR subjects to achieve significantly lower levels of caffeine intake than CF subjects is unfortunately a somewhat equivocal result. On one hand, this finding could indicate that withdrawal distress either did not undermine the efficacy of caffeine fading for CF subjects, or that withdrawal symptoms were not alleviated by relaxation training and therefore resulted in no significant additional benefits for CFR subjects. On the other hand, this relatively straightforward interpretation of the results is complicated by several confounding factors which deserve attention. To begin with, there are grounds for questioning the adequacy of the relaxation training received by CFR subjects, consisting as it did of a single session with the therapist plus tape-recorded instructions. For example, Lehrer (1982), in a recent review of the relaxation literature
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concluded that "tape-recorded instruction appears to be completely ineffective as a m e t h o d for teaching relaxation as a skill that can be used across situations" (p. 417). In addition, although in interview C F R subjects generally reported substantial compliance with the instruction to practice regularly, the absence o f systematic data on the frequency with which the group actually practiced is a weakness o f the study. Similarly, despite the fact that in interview subjects generally reported relatively little withdrawal distress, the absence o f systematic data on withdrawal symptoms is also a weakness. The low frequency o f reported withdrawal symptoms, if reliable, would suggest the u n i m p o r t a n c e o f providing adjunctive treatment such as relaxation training, at least so far as such training is undertaken for the purpose o f facilitating treatment compliance by reducing withdrawal distress. However, it is clear that future caffeine reduction studies should attempt to systematically m o n i t o r the course and degree o f subjects' withdrawal distress. Finally, notwithstanding the failure o f relaxation training to significantly improve the efficacy o f caffeine fading, there was a noticeable trend in the direction o f greater success among C F R subjects. Indeed, the presence of a possible " f l o o r " effect created by the relatively large proportion o f subjects who reached the treatment goal o f five or less cups per day m a y have precluded a significant result being obtained in support o f the addition o f relaxation training to caffeine fading. Considering this and the other reservations m e n t i o n e d above, the therapeutic benefits o f relaxation training for persons following a regimen o f caffeine reduction must be regarded an open question. In summary, then, the present study provides relatively unequivocal support for caffeine fading as a reliable means to effect significant reductions in caffeine use, at least amongst m o t i v a t e d subjects. However, no firm conclusions are warranted concerning the possible additional benefits to be gained from a c o m b i n e d relaxation training/caffeine fading procedure, as distinct from caffeine fading alone.
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FINAL ACCEPTANCE:July 11, 1984