- Email: [email protected]
The tridimensional personality questionnaire: An exploration of personality traits in eating disorders
J.p,j
Ra.. Vol 28. No. 5. pp 413-423. 1994 Copyrght c 1994 Elsewer Saencr Ltd Prmted I” Great Britam All rights reserved 0022~~3956,94 $7 OOf 00
Pergamon 0022-3956(94)00022-O
THE TRIDIMENSIONAL PERSONALITY AN EXPLORATION OF PERSONALITY DISORDERS
QUESTIONNAIRE: TRAITS IN EATING
ERIN I. KLEIFIELD, SUZANNE SUNDAY, STEPHEN HURT and KATHERINE A. HALMI Cornell University Medical College, Westchester Division, White Plains, New York, U.S.A (Rrceirvd
for puhlicalion
3 Max
1994)
Summary---The Tridimensional Personality Questionnaire (TPQ) was tested in four subgroups
of eating-disorder patients: anorectic-restrictors (AN--R). anorectic-bulimics (AN-B), normal weight bulimics (BN). and bulimics with a past history of anorexia (B--AN). Normal controls and patients were matched for gender and age. All subjects completed the Beck Depression Inventory (BDI) in addition to the TPQ. AN-Rs scored lower on the Novelty Seeking scale than the bulimic groups and controls. and the two normal weight bulimic groups had higher Novelty Seeking scores than the controls. On the Harm Avoidance scale. all eating disorder groups scored significantly higher than the control group. In addition. the AN-Rs scored lower than the AN-Bs and B-ANs. The Harm Avoidance scale and depression scores were positively correlated while the Reward Dependence scale and depression scores were negatively correlated. Differences between diagnostic groups on the Novelty Seeking and Persistence scales remained clearly significant when depression was partialled out. These results are discussed in terms of the Tridrmensional Personality Questionnaire as a stable measure of traits with eating disorder subjects.
Introduction THE RELATIVE contribution of genetic, personality, and environmental factors in the development of eating disorders has been formulated within multidimensional models of eating disorders (e.g. Ploog, 1984). However, attempts to find consistencies in personality characteristics within eating disorder subgroups have produced mixed results within the context of the DSM systems (Garner et al., 1990; Schmidt & Telch, 1990; Welch et al., 1990; Yates et al., 1989). This may be due to the limitations of a categorical approach which emphasizes personality disorders (e.g. DSM-III-R criteria). Assessing dimensions of personality may produce more consistent results. The Tridimensional Personality Questionnaire (TPQ) was developed to operationalize and measure behaviors associated with three dimensions of personality: “novelty seeking” (NS-tendency toward intense exhilaration and excitement), “harm avoidance” (HAtendency toward intense avoidance of aversive stimuli), and “reward dependence” (RDtendency toward intense response to rewards, particularly interpersonal rewards). The behaviors associated with these dimensions are reported to be highly routinized and stable within individuals (Cloninger, 1987a,b). The basic psychometric integrity of the TPQ has Correspondence to: Erin I. Kleifield, New York Hospital-Cornell, Road, White Plains, NY 10605. U.S.A. 413
University
Medical College. 21 Bloomingdale
414
E. I.
KLHFIELD
et al
received empirical support in investigations using nonclinical samples (see Cloninger, 1987a; Svrakic et al., 1991). In limited application with clinical samples of obsessiveecompulsive patients (Pfohl et al., 1990) and in a prospective longitudinal investigation predicting early onset alcohol abuse (Cloninger et al., 1988), the dimensions of the TPQ were found to be useful in making predictions of personality styles derived from the descriptive. clinical literature. The TPQ may have particular relevance to the eating disorders. A dimensional analysis may highlight differences among subtypes of eating disorder patients and normal controls that have been obscured by more traditional categorical approaches such as those of the DSM. Further, the descriptions of eating disorder patients found in the DSM parallel the TPQ sca!es. Patients with eating disorders are commonly believed to demonstrate extremes of personality characteristics and such beliefs have been documented in the descriptive, clinical literature. These observations also have received some support in empirical investigations. Bulimic patients have been found to show a tendency to engage in impulsive and antisocial behaviors (e.g. lying, stealing), to have associated substance abuse problems. to show prominent mood lability and poor self-control, and to have interpersonal difficulties (Garner et al.. 1990; Norman & Herzog, 1984; Russell, 1979: Williamson et al., 1985). The theoretical model on which the TPQ was founded suggests that these behaviors are the result of an underlying tendency to seek out experiences that produce exhilaration and excitement. a tendency reflected in ‘he NS scale of the TPQ. Anorectic patients. on the other hand, have been found to display a temperamental disposition toward behavioral and emotional restraint combined with a strong belief in conventional values (Casper, 1990). Strober (1980) found anorcctic patients to demonstrate an obsessional character structure marked by heightened industriousness and responsibility. highly regimented behavior. and rigid adherence and excessive conformance to rules and standards. He also found anorectics to be interpersonally insecure and to show minimal affect. These behaviors are also relevant to the dimensions of the TPQ and anorectic patients should be characterized by low scores on NS and high scores on the Persistence (P) subscale of the RD scale. The TPQ has additional relevance as an instrument for assessing differences among eating disorder subgroups and normal controls beyond its relationship to characterological descriptions. Cloninger (1987b) originally constructed the TPQ as a possible behavioral indicator of noradrenergic (RD). dopaminergic (NS) and scrotoncrgic (HA) functioning. Neurophysical studies of patients with eating disorders have demonstrated differences in neurotransmitter functioning (e.g. Kaye et al., 1991; McBride et al., 1991). If these differences can be linked to behavioral differences assessed by the TPQ, additional opportunities to clarify the interrelationships of these neurotransmitter systems becomc possible on a behavioral level. Although the descriptive and empirical literature lend support to the commonality of personality characteristics of eating disorder patients, few investigations have been conducted using the TPQ with eating disorder subjects. In one study examining the TPQ with bulimic patients. Wailer et al. (1991) found elevated NS and HA. and low RD scores in these patients. In another report (Brewerton et al., 1993). the scores of bulimics (not
TPQ IN EATINGDISORDERS
415
differentiated by past history of anorexia), anorectics, and patients with both anorexia and bulimia were compared to female controls. Results showed that all subtypes of eating disorder patients scored significantly higher on HA, than controls. In addition, BN patients had significantly higher levels of NS and AN patients had significantly higher P scores. While these studies suggest that the TPQ may be a useful instrument with eating disorder patients, the small numbers of subjects in some of the diagnostic subgroups and the failure to take into account other comorbid states which have been shown to affect the TPQ (i.e. depression) compromise the results. Present state factors should be accounted for before conclusions about more enduring differences in personality can be drawn. Several reports have indicated that state variables such as anxiety and depression significantly affect patient’s responses on personality inventories (see Loranger et al., 1991). This issue has special relevance for assessing personality dimensions among eating disorder subjects hospitalized for treatment because of the high levels of depression typically reported in these patients (e.g. Swift et al., 1986). Furthermore, with respect to the TPQ, there is recent evidence (Brown et al., 1992) indicating that the HA scale is affected by current state conditions of anxiety and depression. The purpose of this paper was to evaluate the utility of the TPQ to distinguish personality characteristics among four subtypes of eating disorder patients with anorexia and bulimia. This was accomplished by controlling for the effects of current levels of depression, and comparing these subgroups with normal control subjects. Methods Subjects The eating disorder subjects were 97 females hospitalized for an eating disorder on the Eating Disorders unit at the Cornell Medical Center-Westchester Division. The patients were divided into four subgroups based on current and historical eating disorder diagnosis (according to DSM-III-R): anorectic-restrictors, those with a present diagnosis of anorexia and no history of bulimia (AN-R; n = 29) anorectic-bulimics, those with a present diagnosis of anorexia and bulimia (AN-B; n = 21) bulimics with no history of anorexia (BN; n = 27) and bulimics with a past history of anorexia (B-AN; n = 20). As hospitalized patients, these eating disorder patients represent a small segment of the eating disorder population in the U.S. Control subjects were recruited from a local college and the community through advertisement. Potential subjects completed a screening questionnaire which assessed current and prior weight status, dietary habits, drug history, psychiatric history, and family history. Subjects were included in the study if they did not have a current or past history of an eating disorder or obesity, substance abuse, or psychiatric illness, and were currently at a normal weight. Fifty-one subjects met the inclusion criteria. All 51 subjects completed the TPQ and BDI questionnaires and were included in the study. Measures
The Tridimensional Personality Questionnaire (TPQ, Cloninger, 1987a) is a 100 item questionnaire comprised of true/false questions designed to assess, as originally conceived,
three dimensions of personality: Novelty Seeking (NS). Harm Avoidance (HA), and Reward Dependence (RD). These higher-order dimensions are comprised of lower-order subscales. The NS scale is comprised of: Exploratory Excitability (NSI), Impulsivity (NS2). Extravagance (NS3), and Disorderliness (NS4). Thus. individuals scoring high on the NS scale tend to be curious, impulsive, quick-tempered, and disorderly, whereas those low on the NS scale tend to be reflective, stoical, slow-tempered and orderly. The four HA subscales are: Worry!‘Pessimism (HA I), Fear of Uncertainty (HA2). Shyness with Strangers (HA3), and Fatigability;‘Asthenia (HA4). Individuals high on the HA scale tend to be apprehensive. shy, pessimistic and fatigable, whereas those low on the HA scale tend to be optimistic. carefree. outgoing and energetic. Cloninger and his colleagues have recently revised the RD scale so that the Persistence subscale has been removed and analyzed as a separate scale. Factor analyses in two recent investigations (Svrakic et al.. I99 I ; Kleitield et al.. 1993) revealed that the P subscale formed a separate factor from the remaining RD subscales. In this paper, P is treated as a separate scale and RD is comprised of the remaining three subscales. including: Sentimentalit> (RDI ). Attachment (RD3). and Dependence (RD4). Individuals high on the RD scale tend to be sentimental, socially sensitive, and tender-hearted. whereas those low on the RD scale tend to be insensitive, practical, tough-minded and detached. The P scale measures persistence at non-socially mediated tasks. Individuals scoring high on this scale are determined and resolute; those scoring low give up easily and arc irresolute. The Beck Depression Inventory (BDI) (Beck et al., I Y61). consists of 21 items rctlccting symptoms and cognitions associated with depression. A score of I I I6 indicates mild mood disturbance. I7 20 borderline clinical depression, and 2 I 30 moderate depression. Scores over 30 indicate severe dcprcssion.
All subjects completed the TPQ and BDI questionnaires within 2 weeks of hospital admission. For the anorcctic subjects. the weight gain protocol began after I week 01‘ hospitalization. Thus. for the majority of anorectic subjects, testing preceded cntrancc into the weight gain protocol. For the bulimic subjects. the program is designed to pracnt bingeing and purging and to establish weight maintcnancc. Control subjects completed the questionnaires following determination of their non-clinical status.
To investigate how subgroups of eating disorder patients dilrered on personality characteristics measured by the TPQ, analyses of variance (ANOVAs) wcrc conducted on each of the TPQ scales. Then. because of the significant diff‘erence between groups on levels of depression. and previous evidence indicating that depression significantly influences some TPQ scales (Svrakic et al.. IYYI ). covariance analyses (ANCOVAs) wcrc performed on each of the TPQ scales with BDI scores as the covariate. A priori. single degree of freedom, simple. pairwise contrasts were conducted following the ANOVAs and the ANCOVAs. While such a procedure as the Bonfcrroni correction is a widely accepted procedure for evaluating mean differences when multiple post-hoc comparisons arc carried out, it is an
TPQ IN EATING
417
DISORDERS
inferior procedure to preplanned, single degree of freedom comparisons after achieving significance with an overall F test. Because our hypotheses were a priori and could be evaluated with a priori comparisons, we report these data. Pearson correlations were also calculated to determine the relationships between the TPQ scales and the BDI. All analyses were generated with Systat version 5. I.
Results Table I shows the mean age and BDI score for the eating disorder subgroups and the control subjects. For the eating disorder subgroups, weight (shown as percent of ideal weight at current weight) is also shown. There were no significant differences in age between the five groups. As expected, there were significant differences in weight between the eating disorder subgroups [F(3,93) = 57.49. p < .OOl], with both of the anorectic groups (AN-R and AN-B) significantly lower in percent of ideal weight than the BN and B-AN groups [F(1,93) = 156.06. p < .OOl]. The AN Rs were also significantly more emaciated than the AN-Bs [F( 1,93) = 6.88, p < ,011. The BN and B-AN groups did not differ in current body weight. Depression scores (BDI) differed significantly between diagnostic groups [F(4,142) = 35.61, p < .OOl]. Patients with bulimia and either current or past anorexia were significantly more depressed than the average patient with either anorexia OY bulimia alone (AN-B group: [F(l,142) = 16.44, p < .OOl]: B&AN group: [F(1,142) = 27.96, p < .OOl]. All eating disorder groups were significantly more depressed than the control group [F(I,142) = 130.83, p < .OOI]. The means ( f SD) for the TPQ scales appear in Table 2. The ANOVAs revealed significant differences between diagnostic groups on all TPQ scales. On the NS scale. the AN-R group had the lowest mean score which was significantly lower than the mean score for the control group [F(1,144) = 6.64. p < ,011 and was significantly lower than the mean score for the remaining three patient groups [F(I. 144) = 17.89. p < .OOI]. The two normal weight bulimic groups (BN and B-AN) scored significantly higher than the control group [F(I.144) = 5.8, p < ,051. On the HA scale, control subjects had the lowest mean score and were significantly lower than the patient groups [F(1,144) = 38.19. p < .OOl]. Among the patient groups, the
Mean age Mean percent of ideal weight at current weight Beck score
Anorectic Restrictors (II = 29)
AnorecticBulimics (n = 21)
14.6 (9.1) 74.0 (13.2)
23.7 (5.6) x4.0 (11.3)
22.0 (12.9)
30.8 (15.8)
Bulimics (II = 28) 24.7 (-5.4)
Bulimics--h.u Anorexia (II = 20)
Controls (II = 51) 24.7 (7.5)
(14.0)
23.7 (6.1) 116.6 (14.5)
21.6 (11.8)
33.2 (14.6)
4.3 (4.3)
I 10.0
418
E. 1. KL~IFIELL>et al
AnorecticRestrictors (I/ = 2’))
Anorectic Bulimics (n = ?I)
NS*
12.x
HA**
(4.Y) 17.4
16.1 (6.0) 22.0
(7.1) 14.4 (3.1) 6.8
(6.X) 13.6 (3.1) 5.1
(1.6)
(1.X)
RDf ps
Bulimics (U = 27) 18.7 (5.1) lY.5 (X.0) Ii.7 (3.X) 5.5 (2.0)
Bulimics--/7.\. Anorexia (II = 20) IX.3 (5.3) 20.‘) (6.4) I7 7 (4.‘)) 6.0 (1.X)
Controls (PI = 51) IS.0 (4.6) 12.7 (5.6) IS.6 (3.5) 5.6 (I .Y)
*F(4.141) = 5.3Y.p < .()()I. **F’(4.141) = lO.64.p < .OOl. $F(4,141) = 13.3l.p < .()S. $f14.141) = 2.37. ,I < .05.
ANY Rs showed the lowest mean score which was significantly lower than that of the two combined diagnostic groups [F( 1,144) = 6.34, p < ,011. On the RD scale, the bulimic groups (AN B, BN. and B-AN) scored the lowest and were significantly lower than the control group [F(1,144) = 10.X2. p < .OOl]. The mean score for the AN-R group was higher than that of the bulimic groups and below that of the control group. On the P scale. the mean scores of patients with a current diagnosis of anorexia only (AN--R). or a past history of anorexia with current bulimia (B- AN), were the highest of the patient groups. The AN-Rs had a mean score that was significantly higher than those of the AN -B, BN and control groups [F( 1.144) = 8.69, p < .Ol]. The results of the ANCOVAs varied from those of the ANOVAs only for the HA and RD scales. Scores on these two scales were significantly correlated with BDI scores [F = .5X. F( 1.141) = 26.74.~ < ,001 and r = -.33, F( 1.141) = 6.49,/l < .01. respectively]. All analyses of between groups differences after adjustment for the BDI scores were nonsignificant for the HA and RD scales. Because the scores on the BDI and the NS and P scales were not significantly correlated. covariate adjustment made no difference in the results of the ANOVAs reported above. Discussion This study was designed to measure personality traits from a dimensional perspective with eating disorder subjects. The primary hypotheses of this study. that subgroups of eating disorder patients would differ from one another, and differ from the normative sample on TPQ personality dimensions, were supported by the ANOVAs conducted on the major TPQ scales. Overall, the most consistent differences that emerged among diagnostic groups were between the AN--Rs and bulimic groups. AN-Rs and controls, and bulimic groups and controls. The dual diagnosis patients in this study (AN-Bs and B-ANs) responded more
TPQ IN EATING DISORDERS
419
like those who are only bulimic (BNs) than those who are purely anorectic (AN-Rs). This same finding has been documented in a number of other studies (for review, see DaCosta & Halmi, 1992) and lends support for distinguishing these groups of anorectics. Furthermore, the pattern of TPQ personality traits among eating disorder patients, differs from those observed in the normal population. The relationships observed here between the NS dimension and anorexia nervosa, and NS and bulimia nervosa validate, and perhaps suggest a mechanism for, the descriptive accounts of these disorders presented in the clinical literature. Anorectics are noted for their tendency to demonstrate an obsessional character structure marked by heightened industriousness and responsibility, highly regimented behavior, and rigid adherence and excessive conformance to rules and standards (Strober, 1980). In contrast, clinical reports depict bulimics as externalizers who are impulsive and quick-tempered (e.g. Garner et al., 1990). In line with these accounts, the AN-Rs in this study were significantly more reflective. orderly and obsessional (low NS scores) than the bulimic groups and the controls. Moreover, while all bulimic groups had elevated NS scores relative to the AN-Rs, the two normal weight bulimic groups (BN and B-AN) also had higher NS scores than the controls. The BN patients in the studies by Waller et al. (1991) and Brewerton et al. (1993) also exhibited high levels of NS. Cloninger (1987b) hypothesized that NS reflects behavioral activation which in turn is principally modulated by the neuromonoamine dopamine. Cloninger noted that spontaneous exploratory behavior by mammals in a novel environment depends on the integrity of mesolimbic dopaminergic projections and that dopamine agonists facilitate behavioral activation. As mentioned in the Introduction, bulimics have a tendency to engage in impulsive and antisocial behaviors which could well represent an underlying tendency to seek out experiences that produce exhilaration and excitement, a tendency reflected in the NS scale of the TPQ. Dopaminergic systems are necessary for self-administration behaviors and could be a major link in the role of food as a reinforcer. There is evidence of increased hypothalamic dopamine turnover during feeding (Heffner et al., 1986) which suggests that central dopamine mechanisms mediate rewarding effects of food as they mediate rewarding effects of intracranial self-stimulation and self-administration of psychoactive drugs. The bulimics’ impulsive and anti-social behaviors and binge eating behavior may represent a dysregulation of the dopaminergic neurotransmitter system. The bulimic eating disorder subgroups were significantly higher on the NS dimension than the AN-Rs who display a temperamental disposition toward behavioral and emotional restraint. Results of the ANOVAS on the HA scale revealed that all eating disorder groups scored significantly higher than the controls, and that the AN-Rs scored lower than the two combined diagnosis groups (AN-Bs and BPANs). Waller et al. (199 1) and Brewerton et al. (1993) also found increased HA scores among their BN, and AN, AN-B and BN patients. respectively. Cloninger (1987b) hypothesized that HA, or behavioral inhibition, is related to serotonergic activity which also facilitates satiety. Bulimics have a defect in satiety responses (Halmi & Sunday, 1991). and show evidence of serotonergic dysfunction (McBride et al., 1991). Anorectic patients who exhibit emotional restraint and have an obsessional character structure may have increased serotonergic activity (Kaye et al., 1991).
The complication in u sitnple picture of anorectics having increased serotonin activity and bulimia having decreased serotonin activity is that bulimia nervosa patients. as a group. have the sane increased prevalence of anxiety disorders as do the anorectic patients when cotnparcd to a control population (Braun et al.. 1994). This means there are at Lust two behaviors in bulimia that are influenced by serotonin: eating bchnviors and anxiety syndrome behaviors. Therefore. the role of serotonin function in bulimia nervosa patients is complex. On the RD scale, the three bulimic groups scored significantly lower than the normative sample. On Ihc P scale (formerly a subscale of RD). the AN Rs scored signiticantly highct than the AN -Bs, BNs and controls. Cloninger (19X7b) hypothesked that RD represents variation in behavioral maintenance, or rcsistancc to extinction of previously remarded behavior. Consistent with this formulation. anoreclics are typically obsessional with :I rigid adherence to their beliefs and have highly regimented behaviors. Cloningcr further suggests. on the basis of animal and human studies. Ihat RD is modulated by the noradrenergic neurotr~tnstnitter system (Cloninger. 1987b). It is noteworthy that norepinephrine has a role in regulating feeding behavior within the paraventricular nucleus (PVN). the lateral hypothalamus, and in the perifornical hypothalamus. Abnormalities in noradrcnct-gic activity have been found in both anorcctic and bulimic patients (Kaye et al., IWO. 1984). The persistent low CSF norepinephrinc levels in longterm. so-called weight restored anorcctics. needs an explanation. Does this merely reflect continued aberrant eating behavior and dieting? If so, how does decreased noradrcnergic activity afl‘ect and sustain abnormal eating beha\ ior? The three neurotransliiitters (dopamine. serotonin, and norepincphrine) associated with the personality ditnensions of NS. HA. and RD arc all involved in regulating feeding beha\.ior. The studies of‘ neurotransmitter function in eating disorder patients mentioned above arc preliminary investigations in this arca. These initial promising tindings warrant further and tnore extensive investigations in eating disorder patients of the biological basis for the three dimensions of pcrxonnlity defined by C’loninget-. Further questions are raised by the significant impact of depression on some TPQ dimensions. In the present study, the current level of depression exerted a significant ctfect on the HA and RD scales. but not on the NS or P scales. The results here corroborate those from a longitudinal assessment of the TPQ conducted \vith depressed patients o\et three months of treatment (Brown et al.. IW?). Thcsc investigators also found that traits measured by the HA scale were influenced by states of anxiety and depression. \n,hile It-ails measured by the NS scale remained relatively stable. These findings raise interesting questions about uhcther there arc common biochemical and depression. The norepincphrine substrates mediating the HA and RD dimensions hypothesis of depression postulates that some fortns of depression are attributable to ;I relative deficiency of norepinephrinc ;tt central synapses. Others have proposed an analogous serotonin hypothesis of depression (e.g. Brown et al.. 1991). T~LIS, it may be that dysregulation of the scrotonergic system corresponds to cle\.ations in both depression and HA. while dysregulation in the noradrenergic system corresponds to dysfunction both in depression and RD. One approach to testing this notion would be to obser\,c how changes in depression over Cmc correlate with changes on TPQ scales.
421
TPQ IN EATING DISORDERS
A recent study (Kleifield et al., 1994) provides suggestive evidence to support this hypothesis. In this study, the relationship between depression, changes in depression over time, and changes on the TPQ scales over time were measured. A significant relationship was observed between mood and HA; any group differences and treatment effects on this scale were traceable to levels of, and changes in levels of depression. Mood affected RD in much the same way, suggesting that these scales are sensitive to changes in depression over time. The NS and P scales were unaffected by depression or treatment. Because the HA and RD scales seem especially sensitive to the effects of current mood states, prospective studies to assess changes in these scales as mood improves under treatment would be required. Before discussing the implications of TPQ responses for the clinical management of eating disorder patients, two caveats should be issued. First, because the findings of this study are correlational, it remains to be determined whether the presence of novelty seeking traits are operative in the formation of bulimic behaviors, or merely an outcome of bulimia. Likewise. in the case of anorexia, it remains to be determined whether the tendency for AN-Rs to persist at activities with a higher threshold for fatigue precedes or results from the anorectic condition. Prospective studies would be useful in this regard. Second, the validity of the TPQ in predicting response to treatment and treatment outcome has yet to be determined. This is necessary before statements can be made about appropriate treatment strategies for particular patient groups. Nevertheless, the current findings bear on our understanding of the personality structure and treatment of patients with eating disorders. First, the fact that restricting anorectics exhibit dimensional traits most distinct from the other groups, including those patients who are both anorectic and bulimic, suggests that a specially tailored treatment approach for these patients is needed. Regarding the style and tone of treatment. given the personality style of anorectic patients and their penchant for highly regimented and orderly behavior, they would be likely to respond well to treatment that is well structured with clearly specified goals. These goals should be carefully articulated and manageable; patients should successfully complete one goal before proceeding to the next. In addition to the obvious goal of weight restoration, specific psychosocial treatment goals should include helping these patients not persist so tenaciously and obsessively at non-socially mediated tasks, decrease rigid, black and white thinking and open options and explore alternatives. Second, these data underscore the importance of considering state variables such as depression before drawing conclusions about steadfast personality traits of eating disordered women because many personality variants are exaggerated by current state of depression. Likewise. treatment of depression must be a priority when treating the eating disordered patient.
.4c,k,ro11./[,c!yer,lent.v~The authors wish to thank Drs C Robert Cloninger contributions to thts study. Reprint requests should be sent to Dr Erin I. Kleifield. New York Hospital 21 Bloomingdale Road, White Plains. New York. 10605.
and Thomas Cornell
R. Przyheck
University
for their
Medical College.
References Beck. A. T., Ward. C. H.. Mendelson. M.. Mock. J.. & Erbaugh. ‘I l~:~/?iw.\O/‘Gw~w/I P~r~~hicrrr~. 4, 5S63.
J.
(1961).An inventory for measuring
depression.
422
E. I. KI.EIFIELD et al.
Braun, D.. Sunday, S. R., & Halml. K. A. (lYY4). Psychiatric comorbidity in patients with eating disorders. P.~~d~~lo,yic~ulMrdicine, In press. Brewerton, T. D., Hand. L. D., & Bishop, E. M. Jr. (1993). The tridimensional personality questionnaire in eating disorder patients. lntrrnationnl Journcrl of Eating Disord~w. 14, 213 ~218. Brown, S. L.. Bleich, A.. & van Praag, H. M. (1991). The monoamine hypothesis of depression: The role of serotonin. In S. L. Brown & H. M. van Praag (eds.) 7% role of rwotor~in in p.v~~c~hicrt,-ic~ o’i.w,rkw.s. New York: Brunner:Marel. Brown, S. L.. Svrakic. D. M., Przybeck, T. R.. & Cloninger. C. R. (1992). The relationship of personality to mood and anxiety states: A dImensiona approach. Journcrl o/‘P.s~c~hirrtric R~~.wcrrd~.26, 192-21 I. Caspcr, R. C. (1990). Personality features of women with good outcome from restricting anorexia nervosa. P~,,c,ho.vonltrtic, Mdicinc,. 52, I56 170. Clomnger. C. R. (lY87a). A systematic method for clinical description and classitication of personality variants. ilwl7iw.s o/ Grrwrrl Ps,~chicrr~~~,44, 573-588. Cloningcr. C. R. (lY87b). Neurogcnetic adaptive mechanisms in alcoholism. S&rw, 236, 410-416. Cloninger. C. R.. Sigvardsson. S.. & Bohman. M. (1988). Childhood personality predicts alcohol abuse in young adults. AIddi.nx Clinicd crnciEspc~r.irmwtol Re.xwtd~. 12, 494~ 505. DaCosta. M.. & Hahni. K. A. (1992). Classifications of anorexia nervosa; questlon of subtypes. Ir~rwrwtiorrtrI Jowwrl o/‘&/&/ ni.sort/w.v. I I) 305 3 13. Garner. D. M.. Ohnsted, M. P.. Davis. R.. Rockert. W.. Goldhloom. D., & Eagle. M. (1990). The association hetwjeen bulimic symptoms and reported psychopathology. Inrcwclrio/tal Jowwl of Ea/ir?g L)i.vo~clc~~.s. 9, I 15. Halmi, K. A.. & Sunday. S. R. (1091). Temporal patterns of hunger and fullness ratings and related cognitionh in anorexia and bulimia. .4/~/wfilc. 16, 219 237. Heffner. T. G. Hartman. J. A., & Seiden. L. S. (1986).Dopamine turnover in feeding. S~~icwc. 208, I 16X-l 170. Kaye, W. H.. Guirtsman. H. E.. & George. D. T. (1991). Altered serotonin actiwty 117anorexia nervosa after long-term weight restoration. ilwhiw.\ of (;c/~~LI/ P.\,u hirrr~~~~. 48, 556-562. Kaye. W. H.. Ehert. M. H.. & Gwirtsman. H. E. (1990). CSF monoamine Ic\cls in normal weight bulimia and ewdence for abnormal noradrenergic activity. Anw~%zn Jow?tr/ of Pvd~iarr~~. 147, 225 23Y. Kaye, W. H., Ebert, M. H.. & Raleigh. M. (1984). Abnormalities in CNS monoamine metabolism 111anorexia nervosa. Awhirc,s of tiwwal P.c,~dficr/r~~.41, 350 -3 55. Kleifield, E. 1.. Sunday. S.. Hurt, S.. Br Halmi. K. A. ( 1903). Psychometric validation of the tridimenslonal personality questionnaire: Application to subgroups of eating disorders. C’o/,r/“r’/~l,n.~;~.~,P.c~d?/tr/r~,. 34, 249 253. Kleifield, E. 1.. Sunday. S.. Hurt, S. Bi Hahni. K. A. (lYY3). The effects ofdeprealon and treatmsnt on the TPQ. Biolqqic~crl P.\~h;u~,‘~~. 36, 6X 70. Loranger. A. W.. Lenzenweger. M. F.. Gartner. A. I-‘.. Susman, V. L.. Herzig. J.. Zammlt. <;. K.. Gartner. J. D.. Abrams. R.. & Young. R. C. (I99 I). Trait-state ertlfacts and the diagnosis of personality disorders. .4w/riw.\ of’ Gcnrrcrl P.y~c/lic//~~~,48, 720~-728. McBride, P. A.. Anderson. G M.. Khait, V.. Sunday. S.R.. & Halmi. K. A. (IYY I). Serotonerglc responsivitl in eating disorders. P.~~~hophrr~i?f~~~~~/~~~~, Rullcrin. 27, 365- 372. Norman. D. K.. & Herzog. D. B. (1984). Persistent social maladjustments 111bulimia: A one-year Ihllowup. Auwrium Joutxtrl of I’.\ drirrrr,v, 141, 444 446. Pfohl, B., Black. D.. Noyes. R. Jr., Kellcy, M.. & Blum, N. (1990). A test of the tridimenaional personalit) theory: .4ssociation with diagnosis and platelet imipramlne hlnding in obsessiw compulsive disorder. Bi~~/qqia/ P.\Jdlirl/,‘~. 28, 4 I --46. and endocrine studies for the undcrstandmg of Ploog. D. (1984). The importance of physiologic. metabolic, anorexia nervosa. In K. M. Pirke & D. Ploog (Ed?.). Tl,c /,\~,[,hohio/~!r/~. of wow\-w wwo.w (pp. I 3). Ne\r York: Springer.
nonbulimic binge Schmidt. N. B.. & T&h. M. J. (1990). Prevalence of personality disorders amon g bulimia. eaters, and normal controls. Jwr/rtr/ (!f P.\?,c,/lo/‘f/‘l’/~/o~~,& R&~r~iow/ .4s.vcssnwuf. 12, I69 185. Strober. M. (1980). Personality and symptomatological features In young, nonchronic anorexia nervosa patients. Jounrcrl o/ Ps,~c~ho.son~crtic~ R~wwc~/~, 24, 353-359. Svrakic. D. M., Prrvbeck. T. R., & Clomnger. C. R. (I90 I). Further contribution to the conceptual validity of the unified biosocial model of personality; U.S. and Yugosla\ data. (‘~,nl/,~c,/lerr.sir.~, P.s~~hicrt~~~: 32, lY5 2Oi. Swift. W. J., Andrew, D.. & Barklagc. N. E. (1986). The relationship betbeen aKe&ve disorder and eating disorders: A rcvicw of the literature. AIW~IW~I Jourrwl o/‘P.syd~irr/r~~. 143, 290-299. Wailer, D. A.. Petty, F., Hardy. B. W.. Gullion, C. M.. Murdock, M. V., & Rush. A. J. (1991). Tridimensional personality questionnaire and serotonin in bulimia nervow. Bio/oyic~c~/P.\dlicrtrl~. 29, 55A.
TPQ IN EATING DISORDERS
423
Welch, G., Hall, A., & Renner, R. (1990). Patient subgroupings in anorexia nervosa using psychologically-based classification. Iniernational Journal of Eating Disorder.?, 3, 31 l-322. Williamson, D. A.. Kelley, M. L., Davis, C. J., Ruggiero. L., & Blouin, D. C. (1985). Psychopathology of eating disorders: Controlled comparison of bulimic. obese, and normal subjects. Journal of Consulting und Clinical Psychology,
53, I6
I-
166.
Yates, W. R., Sieleni, B., & Bowers, W. A. (1989). Clinical correlates International
Journal
gfEating
Disorders.
8,413471.
of personality
disorder
in bulimia
nervosa.
Ra.. Vol 28. No. 5. pp 413-423. 1994 Copyrght c 1994 Elsewer Saencr Ltd Prmted I” Great Britam All rights reserved 0022~~3956,94 $7 OOf 00
Pergamon 0022-3956(94)00022-O
THE TRIDIMENSIONAL PERSONALITY AN EXPLORATION OF PERSONALITY DISORDERS
QUESTIONNAIRE: TRAITS IN EATING
ERIN I. KLEIFIELD, SUZANNE SUNDAY, STEPHEN HURT and KATHERINE A. HALMI Cornell University Medical College, Westchester Division, White Plains, New York, U.S.A (Rrceirvd
for puhlicalion
3 Max
1994)
Summary---The Tridimensional Personality Questionnaire (TPQ) was tested in four subgroups
of eating-disorder patients: anorectic-restrictors (AN--R). anorectic-bulimics (AN-B), normal weight bulimics (BN). and bulimics with a past history of anorexia (B--AN). Normal controls and patients were matched for gender and age. All subjects completed the Beck Depression Inventory (BDI) in addition to the TPQ. AN-Rs scored lower on the Novelty Seeking scale than the bulimic groups and controls. and the two normal weight bulimic groups had higher Novelty Seeking scores than the controls. On the Harm Avoidance scale. all eating disorder groups scored significantly higher than the control group. In addition. the AN-Rs scored lower than the AN-Bs and B-ANs. The Harm Avoidance scale and depression scores were positively correlated while the Reward Dependence scale and depression scores were negatively correlated. Differences between diagnostic groups on the Novelty Seeking and Persistence scales remained clearly significant when depression was partialled out. These results are discussed in terms of the Tridrmensional Personality Questionnaire as a stable measure of traits with eating disorder subjects.
Introduction THE RELATIVE contribution of genetic, personality, and environmental factors in the development of eating disorders has been formulated within multidimensional models of eating disorders (e.g. Ploog, 1984). However, attempts to find consistencies in personality characteristics within eating disorder subgroups have produced mixed results within the context of the DSM systems (Garner et al., 1990; Schmidt & Telch, 1990; Welch et al., 1990; Yates et al., 1989). This may be due to the limitations of a categorical approach which emphasizes personality disorders (e.g. DSM-III-R criteria). Assessing dimensions of personality may produce more consistent results. The Tridimensional Personality Questionnaire (TPQ) was developed to operationalize and measure behaviors associated with three dimensions of personality: “novelty seeking” (NS-tendency toward intense exhilaration and excitement), “harm avoidance” (HAtendency toward intense avoidance of aversive stimuli), and “reward dependence” (RDtendency toward intense response to rewards, particularly interpersonal rewards). The behaviors associated with these dimensions are reported to be highly routinized and stable within individuals (Cloninger, 1987a,b). The basic psychometric integrity of the TPQ has Correspondence to: Erin I. Kleifield, New York Hospital-Cornell, Road, White Plains, NY 10605. U.S.A. 413
University
Medical College. 21 Bloomingdale
414
E. I.
KLHFIELD
et al
received empirical support in investigations using nonclinical samples (see Cloninger, 1987a; Svrakic et al., 1991). In limited application with clinical samples of obsessiveecompulsive patients (Pfohl et al., 1990) and in a prospective longitudinal investigation predicting early onset alcohol abuse (Cloninger et al., 1988), the dimensions of the TPQ were found to be useful in making predictions of personality styles derived from the descriptive. clinical literature. The TPQ may have particular relevance to the eating disorders. A dimensional analysis may highlight differences among subtypes of eating disorder patients and normal controls that have been obscured by more traditional categorical approaches such as those of the DSM. Further, the descriptions of eating disorder patients found in the DSM parallel the TPQ sca!es. Patients with eating disorders are commonly believed to demonstrate extremes of personality characteristics and such beliefs have been documented in the descriptive, clinical literature. These observations also have received some support in empirical investigations. Bulimic patients have been found to show a tendency to engage in impulsive and antisocial behaviors (e.g. lying, stealing), to have associated substance abuse problems. to show prominent mood lability and poor self-control, and to have interpersonal difficulties (Garner et al.. 1990; Norman & Herzog, 1984; Russell, 1979: Williamson et al., 1985). The theoretical model on which the TPQ was founded suggests that these behaviors are the result of an underlying tendency to seek out experiences that produce exhilaration and excitement. a tendency reflected in ‘he NS scale of the TPQ. Anorectic patients. on the other hand, have been found to display a temperamental disposition toward behavioral and emotional restraint combined with a strong belief in conventional values (Casper, 1990). Strober (1980) found anorcctic patients to demonstrate an obsessional character structure marked by heightened industriousness and responsibility. highly regimented behavior. and rigid adherence and excessive conformance to rules and standards. He also found anorectics to be interpersonally insecure and to show minimal affect. These behaviors are also relevant to the dimensions of the TPQ and anorectic patients should be characterized by low scores on NS and high scores on the Persistence (P) subscale of the RD scale. The TPQ has additional relevance as an instrument for assessing differences among eating disorder subgroups and normal controls beyond its relationship to characterological descriptions. Cloninger (1987b) originally constructed the TPQ as a possible behavioral indicator of noradrenergic (RD). dopaminergic (NS) and scrotoncrgic (HA) functioning. Neurophysical studies of patients with eating disorders have demonstrated differences in neurotransmitter functioning (e.g. Kaye et al., 1991; McBride et al., 1991). If these differences can be linked to behavioral differences assessed by the TPQ, additional opportunities to clarify the interrelationships of these neurotransmitter systems becomc possible on a behavioral level. Although the descriptive and empirical literature lend support to the commonality of personality characteristics of eating disorder patients, few investigations have been conducted using the TPQ with eating disorder subjects. In one study examining the TPQ with bulimic patients. Wailer et al. (1991) found elevated NS and HA. and low RD scores in these patients. In another report (Brewerton et al., 1993). the scores of bulimics (not
TPQ IN EATINGDISORDERS
415
differentiated by past history of anorexia), anorectics, and patients with both anorexia and bulimia were compared to female controls. Results showed that all subtypes of eating disorder patients scored significantly higher on HA, than controls. In addition, BN patients had significantly higher levels of NS and AN patients had significantly higher P scores. While these studies suggest that the TPQ may be a useful instrument with eating disorder patients, the small numbers of subjects in some of the diagnostic subgroups and the failure to take into account other comorbid states which have been shown to affect the TPQ (i.e. depression) compromise the results. Present state factors should be accounted for before conclusions about more enduring differences in personality can be drawn. Several reports have indicated that state variables such as anxiety and depression significantly affect patient’s responses on personality inventories (see Loranger et al., 1991). This issue has special relevance for assessing personality dimensions among eating disorder subjects hospitalized for treatment because of the high levels of depression typically reported in these patients (e.g. Swift et al., 1986). Furthermore, with respect to the TPQ, there is recent evidence (Brown et al., 1992) indicating that the HA scale is affected by current state conditions of anxiety and depression. The purpose of this paper was to evaluate the utility of the TPQ to distinguish personality characteristics among four subtypes of eating disorder patients with anorexia and bulimia. This was accomplished by controlling for the effects of current levels of depression, and comparing these subgroups with normal control subjects. Methods Subjects The eating disorder subjects were 97 females hospitalized for an eating disorder on the Eating Disorders unit at the Cornell Medical Center-Westchester Division. The patients were divided into four subgroups based on current and historical eating disorder diagnosis (according to DSM-III-R): anorectic-restrictors, those with a present diagnosis of anorexia and no history of bulimia (AN-R; n = 29) anorectic-bulimics, those with a present diagnosis of anorexia and bulimia (AN-B; n = 21) bulimics with no history of anorexia (BN; n = 27) and bulimics with a past history of anorexia (B-AN; n = 20). As hospitalized patients, these eating disorder patients represent a small segment of the eating disorder population in the U.S. Control subjects were recruited from a local college and the community through advertisement. Potential subjects completed a screening questionnaire which assessed current and prior weight status, dietary habits, drug history, psychiatric history, and family history. Subjects were included in the study if they did not have a current or past history of an eating disorder or obesity, substance abuse, or psychiatric illness, and were currently at a normal weight. Fifty-one subjects met the inclusion criteria. All 51 subjects completed the TPQ and BDI questionnaires and were included in the study. Measures
The Tridimensional Personality Questionnaire (TPQ, Cloninger, 1987a) is a 100 item questionnaire comprised of true/false questions designed to assess, as originally conceived,
three dimensions of personality: Novelty Seeking (NS). Harm Avoidance (HA), and Reward Dependence (RD). These higher-order dimensions are comprised of lower-order subscales. The NS scale is comprised of: Exploratory Excitability (NSI), Impulsivity (NS2). Extravagance (NS3), and Disorderliness (NS4). Thus. individuals scoring high on the NS scale tend to be curious, impulsive, quick-tempered, and disorderly, whereas those low on the NS scale tend to be reflective, stoical, slow-tempered and orderly. The four HA subscales are: Worry!‘Pessimism (HA I), Fear of Uncertainty (HA2). Shyness with Strangers (HA3), and Fatigability;‘Asthenia (HA4). Individuals high on the HA scale tend to be apprehensive. shy, pessimistic and fatigable, whereas those low on the HA scale tend to be optimistic. carefree. outgoing and energetic. Cloninger and his colleagues have recently revised the RD scale so that the Persistence subscale has been removed and analyzed as a separate scale. Factor analyses in two recent investigations (Svrakic et al.. I99 I ; Kleitield et al.. 1993) revealed that the P subscale formed a separate factor from the remaining RD subscales. In this paper, P is treated as a separate scale and RD is comprised of the remaining three subscales. including: Sentimentalit> (RDI ). Attachment (RD3). and Dependence (RD4). Individuals high on the RD scale tend to be sentimental, socially sensitive, and tender-hearted. whereas those low on the RD scale tend to be insensitive, practical, tough-minded and detached. The P scale measures persistence at non-socially mediated tasks. Individuals scoring high on this scale are determined and resolute; those scoring low give up easily and arc irresolute. The Beck Depression Inventory (BDI) (Beck et al., I Y61). consists of 21 items rctlccting symptoms and cognitions associated with depression. A score of I I I6 indicates mild mood disturbance. I7 20 borderline clinical depression, and 2 I 30 moderate depression. Scores over 30 indicate severe dcprcssion.
All subjects completed the TPQ and BDI questionnaires within 2 weeks of hospital admission. For the anorcctic subjects. the weight gain protocol began after I week 01‘ hospitalization. Thus. for the majority of anorectic subjects, testing preceded cntrancc into the weight gain protocol. For the bulimic subjects. the program is designed to pracnt bingeing and purging and to establish weight maintcnancc. Control subjects completed the questionnaires following determination of their non-clinical status.
To investigate how subgroups of eating disorder patients dilrered on personality characteristics measured by the TPQ, analyses of variance (ANOVAs) wcrc conducted on each of the TPQ scales. Then. because of the significant diff‘erence between groups on levels of depression. and previous evidence indicating that depression significantly influences some TPQ scales (Svrakic et al.. IYYI ). covariance analyses (ANCOVAs) wcrc performed on each of the TPQ scales with BDI scores as the covariate. A priori. single degree of freedom, simple. pairwise contrasts were conducted following the ANOVAs and the ANCOVAs. While such a procedure as the Bonfcrroni correction is a widely accepted procedure for evaluating mean differences when multiple post-hoc comparisons arc carried out, it is an
TPQ IN EATING
417
DISORDERS
inferior procedure to preplanned, single degree of freedom comparisons after achieving significance with an overall F test. Because our hypotheses were a priori and could be evaluated with a priori comparisons, we report these data. Pearson correlations were also calculated to determine the relationships between the TPQ scales and the BDI. All analyses were generated with Systat version 5. I.
Results Table I shows the mean age and BDI score for the eating disorder subgroups and the control subjects. For the eating disorder subgroups, weight (shown as percent of ideal weight at current weight) is also shown. There were no significant differences in age between the five groups. As expected, there were significant differences in weight between the eating disorder subgroups [F(3,93) = 57.49. p < .OOl], with both of the anorectic groups (AN-R and AN-B) significantly lower in percent of ideal weight than the BN and B-AN groups [F(1,93) = 156.06. p < .OOl]. The AN Rs were also significantly more emaciated than the AN-Bs [F( 1,93) = 6.88, p < ,011. The BN and B-AN groups did not differ in current body weight. Depression scores (BDI) differed significantly between diagnostic groups [F(4,142) = 35.61, p < .OOl]. Patients with bulimia and either current or past anorexia were significantly more depressed than the average patient with either anorexia OY bulimia alone (AN-B group: [F(l,142) = 16.44, p < .OOl]: B&AN group: [F(1,142) = 27.96, p < .OOl]. All eating disorder groups were significantly more depressed than the control group [F(I,142) = 130.83, p < .OOI]. The means ( f SD) for the TPQ scales appear in Table 2. The ANOVAs revealed significant differences between diagnostic groups on all TPQ scales. On the NS scale. the AN-R group had the lowest mean score which was significantly lower than the mean score for the control group [F(1,144) = 6.64. p < ,011 and was significantly lower than the mean score for the remaining three patient groups [F(I. 144) = 17.89. p < .OOI]. The two normal weight bulimic groups (BN and B-AN) scored significantly higher than the control group [F(I.144) = 5.8, p < ,051. On the HA scale, control subjects had the lowest mean score and were significantly lower than the patient groups [F(1,144) = 38.19. p < .OOl]. Among the patient groups, the
Mean age Mean percent of ideal weight at current weight Beck score
Anorectic Restrictors (II = 29)
AnorecticBulimics (n = 21)
14.6 (9.1) 74.0 (13.2)
23.7 (5.6) x4.0 (11.3)
22.0 (12.9)
30.8 (15.8)
Bulimics (II = 28) 24.7 (-5.4)
Bulimics--h.u Anorexia (II = 20)
Controls (II = 51) 24.7 (7.5)
(14.0)
23.7 (6.1) 116.6 (14.5)
21.6 (11.8)
33.2 (14.6)
4.3 (4.3)
I 10.0
418
E. 1. KL~IFIELL>et al
AnorecticRestrictors (I/ = 2’))
Anorectic Bulimics (n = ?I)
NS*
12.x
HA**
(4.Y) 17.4
16.1 (6.0) 22.0
(7.1) 14.4 (3.1) 6.8
(6.X) 13.6 (3.1) 5.1
(1.6)
(1.X)
RDf ps
Bulimics (U = 27) 18.7 (5.1) lY.5 (X.0) Ii.7 (3.X) 5.5 (2.0)
Bulimics--/7.\. Anorexia (II = 20) IX.3 (5.3) 20.‘) (6.4) I7 7 (4.‘)) 6.0 (1.X)
Controls (PI = 51) IS.0 (4.6) 12.7 (5.6) IS.6 (3.5) 5.6 (I .Y)
*F(4.141) = 5.3Y.p < .()()I. **F’(4.141) = lO.64.p < .OOl. $F(4,141) = 13.3l.p < .()S. $f14.141) = 2.37. ,I < .05.
ANY Rs showed the lowest mean score which was significantly lower than that of the two combined diagnostic groups [F( 1,144) = 6.34, p < ,011. On the RD scale, the bulimic groups (AN B, BN. and B-AN) scored the lowest and were significantly lower than the control group [F(1,144) = 10.X2. p < .OOl]. The mean score for the AN-R group was higher than that of the bulimic groups and below that of the control group. On the P scale. the mean scores of patients with a current diagnosis of anorexia only (AN--R). or a past history of anorexia with current bulimia (B- AN), were the highest of the patient groups. The AN-Rs had a mean score that was significantly higher than those of the AN -B, BN and control groups [F( 1.144) = 8.69, p < .Ol]. The results of the ANCOVAs varied from those of the ANOVAs only for the HA and RD scales. Scores on these two scales were significantly correlated with BDI scores [F = .5X. F( 1.141) = 26.74.~ < ,001 and r = -.33, F( 1.141) = 6.49,/l < .01. respectively]. All analyses of between groups differences after adjustment for the BDI scores were nonsignificant for the HA and RD scales. Because the scores on the BDI and the NS and P scales were not significantly correlated. covariate adjustment made no difference in the results of the ANOVAs reported above. Discussion This study was designed to measure personality traits from a dimensional perspective with eating disorder subjects. The primary hypotheses of this study. that subgroups of eating disorder patients would differ from one another, and differ from the normative sample on TPQ personality dimensions, were supported by the ANOVAs conducted on the major TPQ scales. Overall, the most consistent differences that emerged among diagnostic groups were between the AN--Rs and bulimic groups. AN-Rs and controls, and bulimic groups and controls. The dual diagnosis patients in this study (AN-Bs and B-ANs) responded more
TPQ IN EATING DISORDERS
419
like those who are only bulimic (BNs) than those who are purely anorectic (AN-Rs). This same finding has been documented in a number of other studies (for review, see DaCosta & Halmi, 1992) and lends support for distinguishing these groups of anorectics. Furthermore, the pattern of TPQ personality traits among eating disorder patients, differs from those observed in the normal population. The relationships observed here between the NS dimension and anorexia nervosa, and NS and bulimia nervosa validate, and perhaps suggest a mechanism for, the descriptive accounts of these disorders presented in the clinical literature. Anorectics are noted for their tendency to demonstrate an obsessional character structure marked by heightened industriousness and responsibility, highly regimented behavior, and rigid adherence and excessive conformance to rules and standards (Strober, 1980). In contrast, clinical reports depict bulimics as externalizers who are impulsive and quick-tempered (e.g. Garner et al., 1990). In line with these accounts, the AN-Rs in this study were significantly more reflective. orderly and obsessional (low NS scores) than the bulimic groups and the controls. Moreover, while all bulimic groups had elevated NS scores relative to the AN-Rs, the two normal weight bulimic groups (BN and B-AN) also had higher NS scores than the controls. The BN patients in the studies by Waller et al. (1991) and Brewerton et al. (1993) also exhibited high levels of NS. Cloninger (1987b) hypothesized that NS reflects behavioral activation which in turn is principally modulated by the neuromonoamine dopamine. Cloninger noted that spontaneous exploratory behavior by mammals in a novel environment depends on the integrity of mesolimbic dopaminergic projections and that dopamine agonists facilitate behavioral activation. As mentioned in the Introduction, bulimics have a tendency to engage in impulsive and antisocial behaviors which could well represent an underlying tendency to seek out experiences that produce exhilaration and excitement, a tendency reflected in the NS scale of the TPQ. Dopaminergic systems are necessary for self-administration behaviors and could be a major link in the role of food as a reinforcer. There is evidence of increased hypothalamic dopamine turnover during feeding (Heffner et al., 1986) which suggests that central dopamine mechanisms mediate rewarding effects of food as they mediate rewarding effects of intracranial self-stimulation and self-administration of psychoactive drugs. The bulimics’ impulsive and anti-social behaviors and binge eating behavior may represent a dysregulation of the dopaminergic neurotransmitter system. The bulimic eating disorder subgroups were significantly higher on the NS dimension than the AN-Rs who display a temperamental disposition toward behavioral and emotional restraint. Results of the ANOVAS on the HA scale revealed that all eating disorder groups scored significantly higher than the controls, and that the AN-Rs scored lower than the two combined diagnosis groups (AN-Bs and BPANs). Waller et al. (199 1) and Brewerton et al. (1993) also found increased HA scores among their BN, and AN, AN-B and BN patients. respectively. Cloninger (1987b) hypothesized that HA, or behavioral inhibition, is related to serotonergic activity which also facilitates satiety. Bulimics have a defect in satiety responses (Halmi & Sunday, 1991). and show evidence of serotonergic dysfunction (McBride et al., 1991). Anorectic patients who exhibit emotional restraint and have an obsessional character structure may have increased serotonergic activity (Kaye et al., 1991).
The complication in u sitnple picture of anorectics having increased serotonin activity and bulimia having decreased serotonin activity is that bulimia nervosa patients. as a group. have the sane increased prevalence of anxiety disorders as do the anorectic patients when cotnparcd to a control population (Braun et al.. 1994). This means there are at Lust two behaviors in bulimia that are influenced by serotonin: eating bchnviors and anxiety syndrome behaviors. Therefore. the role of serotonin function in bulimia nervosa patients is complex. On the RD scale, the three bulimic groups scored significantly lower than the normative sample. On Ihc P scale (formerly a subscale of RD). the AN Rs scored signiticantly highct than the AN -Bs, BNs and controls. Cloninger (19X7b) hypothesked that RD represents variation in behavioral maintenance, or rcsistancc to extinction of previously remarded behavior. Consistent with this formulation. anoreclics are typically obsessional with :I rigid adherence to their beliefs and have highly regimented behaviors. Cloningcr further suggests. on the basis of animal and human studies. Ihat RD is modulated by the noradrenergic neurotr~tnstnitter system (Cloninger. 1987b). It is noteworthy that norepinephrine has a role in regulating feeding behavior within the paraventricular nucleus (PVN). the lateral hypothalamus, and in the perifornical hypothalamus. Abnormalities in noradrcnct-gic activity have been found in both anorcctic and bulimic patients (Kaye et al., IWO. 1984). The persistent low CSF norepinephrinc levels in longterm. so-called weight restored anorcctics. needs an explanation. Does this merely reflect continued aberrant eating behavior and dieting? If so, how does decreased noradrcnergic activity afl‘ect and sustain abnormal eating beha\ ior? The three neurotransliiitters (dopamine. serotonin, and norepincphrine) associated with the personality ditnensions of NS. HA. and RD arc all involved in regulating feeding beha\.ior. The studies of‘ neurotransmitter function in eating disorder patients mentioned above arc preliminary investigations in this arca. These initial promising tindings warrant further and tnore extensive investigations in eating disorder patients of the biological basis for the three dimensions of pcrxonnlity defined by C’loninget-. Further questions are raised by the significant impact of depression on some TPQ dimensions. In the present study, the current level of depression exerted a significant ctfect on the HA and RD scales. but not on the NS or P scales. The results here corroborate those from a longitudinal assessment of the TPQ conducted \vith depressed patients o\et three months of treatment (Brown et al.. IW?). Thcsc investigators also found that traits measured by the HA scale were influenced by states of anxiety and depression. \n,hile It-ails measured by the NS scale remained relatively stable. These findings raise interesting questions about uhcther there arc common biochemical and depression. The norepincphrine substrates mediating the HA and RD dimensions hypothesis of depression postulates that some fortns of depression are attributable to ;I relative deficiency of norepinephrinc ;tt central synapses. Others have proposed an analogous serotonin hypothesis of depression (e.g. Brown et al.. 1991). T~LIS, it may be that dysregulation of the scrotonergic system corresponds to cle\.ations in both depression and HA. while dysregulation in the noradrenergic system corresponds to dysfunction both in depression and RD. One approach to testing this notion would be to obser\,c how changes in depression over Cmc correlate with changes on TPQ scales.
421
TPQ IN EATING DISORDERS
A recent study (Kleifield et al., 1994) provides suggestive evidence to support this hypothesis. In this study, the relationship between depression, changes in depression over time, and changes on the TPQ scales over time were measured. A significant relationship was observed between mood and HA; any group differences and treatment effects on this scale were traceable to levels of, and changes in levels of depression. Mood affected RD in much the same way, suggesting that these scales are sensitive to changes in depression over time. The NS and P scales were unaffected by depression or treatment. Because the HA and RD scales seem especially sensitive to the effects of current mood states, prospective studies to assess changes in these scales as mood improves under treatment would be required. Before discussing the implications of TPQ responses for the clinical management of eating disorder patients, two caveats should be issued. First, because the findings of this study are correlational, it remains to be determined whether the presence of novelty seeking traits are operative in the formation of bulimic behaviors, or merely an outcome of bulimia. Likewise. in the case of anorexia, it remains to be determined whether the tendency for AN-Rs to persist at activities with a higher threshold for fatigue precedes or results from the anorectic condition. Prospective studies would be useful in this regard. Second, the validity of the TPQ in predicting response to treatment and treatment outcome has yet to be determined. This is necessary before statements can be made about appropriate treatment strategies for particular patient groups. Nevertheless, the current findings bear on our understanding of the personality structure and treatment of patients with eating disorders. First, the fact that restricting anorectics exhibit dimensional traits most distinct from the other groups, including those patients who are both anorectic and bulimic, suggests that a specially tailored treatment approach for these patients is needed. Regarding the style and tone of treatment. given the personality style of anorectic patients and their penchant for highly regimented and orderly behavior, they would be likely to respond well to treatment that is well structured with clearly specified goals. These goals should be carefully articulated and manageable; patients should successfully complete one goal before proceeding to the next. In addition to the obvious goal of weight restoration, specific psychosocial treatment goals should include helping these patients not persist so tenaciously and obsessively at non-socially mediated tasks, decrease rigid, black and white thinking and open options and explore alternatives. Second, these data underscore the importance of considering state variables such as depression before drawing conclusions about steadfast personality traits of eating disordered women because many personality variants are exaggerated by current state of depression. Likewise. treatment of depression must be a priority when treating the eating disordered patient.
.4c,k,ro11./[,c!yer,lent.v~The authors wish to thank Drs C Robert Cloninger contributions to thts study. Reprint requests should be sent to Dr Erin I. Kleifield. New York Hospital 21 Bloomingdale Road, White Plains. New York. 10605.
and Thomas Cornell
R. Przyheck
University
for their
Medical College.
References Beck. A. T., Ward. C. H.. Mendelson. M.. Mock. J.. & Erbaugh. ‘I l~:~/?iw.\O/‘Gw~w/I P~r~~hicrrr~. 4, 5S63.
J.
(1961).An inventory for measuring
depression.
422
E. I. KI.EIFIELD et al.
Braun, D.. Sunday, S. R., & Halml. K. A. (lYY4). Psychiatric comorbidity in patients with eating disorders. P.~~d~~lo,yic~ulMrdicine, In press. Brewerton, T. D., Hand. L. D., & Bishop, E. M. Jr. (1993). The tridimensional personality questionnaire in eating disorder patients. lntrrnationnl Journcrl of Eating Disord~w. 14, 213 ~218. Brown, S. L.. Bleich, A.. & van Praag, H. M. (1991). The monoamine hypothesis of depression: The role of serotonin. In S. L. Brown & H. M. van Praag (eds.) 7% role of rwotor~in in p.v~~c~hicrt,-ic~ o’i.w,rkw.s. New York: Brunner:Marel. Brown, S. L.. Svrakic. D. M., Przybeck, T. R.. & Cloninger. C. R. (1992). The relationship of personality to mood and anxiety states: A dImensiona approach. Journcrl o/‘P.s~c~hirrtric R~~.wcrrd~.26, 192-21 I. Caspcr, R. C. (1990). Personality features of women with good outcome from restricting anorexia nervosa. P~,,c,ho.vonltrtic, Mdicinc,. 52, I56 170. Clomnger. C. R. (lY87a). A systematic method for clinical description and classitication of personality variants. ilwl7iw.s o/ Grrwrrl Ps,~chicrr~~~,44, 573-588. Cloningcr. C. R. (lY87b). Neurogcnetic adaptive mechanisms in alcoholism. S&rw, 236, 410-416. Cloninger. C. R.. Sigvardsson. S.. & Bohman. M. (1988). Childhood personality predicts alcohol abuse in young adults. AIddi.nx Clinicd crnciEspc~r.irmwtol Re.xwtd~. 12, 494~ 505. DaCosta. M.. & Hahni. K. A. (1992). Classifications of anorexia nervosa; questlon of subtypes. Ir~rwrwtiorrtrI Jowwrl o/‘&/&/ ni.sort/w.v. I I) 305 3 13. Garner. D. M.. Ohnsted, M. P.. Davis. R.. Rockert. W.. Goldhloom. D., & Eagle. M. (1990). The association hetwjeen bulimic symptoms and reported psychopathology. Inrcwclrio/tal Jowwl of Ea/ir?g L)i.vo~clc~~.s. 9, I 15. Halmi, K. A.. & Sunday. S. R. (1091). Temporal patterns of hunger and fullness ratings and related cognitionh in anorexia and bulimia. .4/~/wfilc. 16, 219 237. Heffner. T. G. Hartman. J. A., & Seiden. L. S. (1986).Dopamine turnover in feeding. S~~icwc. 208, I 16X-l 170. Kaye, W. H.. Guirtsman. H. E.. & George. D. T. (1991). Altered serotonin actiwty 117anorexia nervosa after long-term weight restoration. ilwhiw.\ of (;c/~~LI/ P.\,u hirrr~~~~. 48, 556-562. Kaye. W. H.. Ehert. M. H.. & Gwirtsman. H. E. (1990). CSF monoamine Ic\cls in normal weight bulimia and ewdence for abnormal noradrenergic activity. Anw~%zn Jow?tr/ of Pvd~iarr~~. 147, 225 23Y. Kaye, W. H., Ebert, M. H.. & Raleigh. M. (1984). Abnormalities in CNS monoamine metabolism 111anorexia nervosa. Awhirc,s of tiwwal P.c,~dficr/r~~.41, 350 -3 55. Kleifield, E. 1.. Sunday. S.. Hurt, S.. Br Halmi. K. A. ( 1903). Psychometric validation of the tridimenslonal personality questionnaire: Application to subgroups of eating disorders. C’o/,r/“r’/~l,n.~;~.~,P.c~d?/tr/r~,. 34, 249 253. Kleifield, E. 1.. Sunday. S.. Hurt, S. Bi Hahni. K. A. (lYY3). The effects ofdeprealon and treatmsnt on the TPQ. Biolqqic~crl P.\~h;u~,‘~~. 36, 6X 70. Loranger. A. W.. Lenzenweger. M. F.. Gartner. A. I-‘.. Susman, V. L.. Herzig. J.. Zammlt. <;. K.. Gartner. J. D.. Abrams. R.. & Young. R. C. (I99 I). Trait-state ertlfacts and the diagnosis of personality disorders. .4w/riw.\ of’ Gcnrrcrl P.y~c/lic//~~~,48, 720~-728. McBride, P. A.. Anderson. G M.. Khait, V.. Sunday. S.R.. & Halmi. K. A. (IYY I). Serotonerglc responsivitl in eating disorders. P.~~~hophrr~i?f~~~~~/~~~~, Rullcrin. 27, 365- 372. Norman. D. K.. & Herzog. D. B. (1984). Persistent social maladjustments 111bulimia: A one-year Ihllowup. Auwrium Joutxtrl of I’.\ drirrrr,v, 141, 444 446. Pfohl, B., Black. D.. Noyes. R. Jr., Kellcy, M.. & Blum, N. (1990). A test of the tridimenaional personalit) theory: .4ssociation with diagnosis and platelet imipramlne hlnding in obsessiw compulsive disorder. Bi~~/qqia/ P.\Jdlirl/,‘~. 28, 4 I --46. and endocrine studies for the undcrstandmg of Ploog. D. (1984). The importance of physiologic. metabolic, anorexia nervosa. In K. M. Pirke & D. Ploog (Ed?.). Tl,c /,\~,[,hohio/~!r/~. of wow\-w wwo.w (pp. I 3). Ne\r York: Springer.
nonbulimic binge Schmidt. N. B.. & T&h. M. J. (1990). Prevalence of personality disorders amon g bulimia. eaters, and normal controls. Jwr/rtr/ (!f P.\?,c,/lo/‘f/‘l’/~/o~~,& R&~r~iow/ .4s.vcssnwuf. 12, I69 185. Strober. M. (1980). Personality and symptomatological features In young, nonchronic anorexia nervosa patients. Jounrcrl o/ Ps,~c~ho.son~crtic~ R~wwc~/~, 24, 353-359. Svrakic. D. M., Prrvbeck. T. R., & Clomnger. C. R. (I90 I). Further contribution to the conceptual validity of the unified biosocial model of personality; U.S. and Yugosla\ data. (‘~,nl/,~c,/lerr.sir.~, P.s~~hicrt~~~: 32, lY5 2Oi. Swift. W. J., Andrew, D.. & Barklagc. N. E. (1986). The relationship betbeen aKe&ve disorder and eating disorders: A rcvicw of the literature. AIW~IW~I Jourrwl o/‘P.syd~irr/r~~. 143, 290-299. Wailer, D. A.. Petty, F., Hardy. B. W.. Gullion, C. M.. Murdock, M. V., & Rush. A. J. (1991). Tridimensional personality questionnaire and serotonin in bulimia nervow. Bio/oyic~c~/P.\dlicrtrl~. 29, 55A.
TPQ IN EATING DISORDERS
423
Welch, G., Hall, A., & Renner, R. (1990). Patient subgroupings in anorexia nervosa using psychologically-based classification. Iniernational Journal of Eating Disorder.?, 3, 31 l-322. Williamson, D. A.. Kelley, M. L., Davis, C. J., Ruggiero. L., & Blouin, D. C. (1985). Psychopathology of eating disorders: Controlled comparison of bulimic. obese, and normal subjects. Journal of Consulting und Clinical Psychology,
53, I6
I-
166.
Yates, W. R., Sieleni, B., & Bowers, W. A. (1989). Clinical correlates International
Journal
gfEating
Disorders.
8,413471.
of personality
disorder
in bulimia
nervosa.