Scaling of life events by psychiatric patients and normals

Journal of PsychosomaticResearch,

Vol. 20, pp. 141 to 149. Pergamon

Press, 1976. Printed

n Great Britain

SCALING OF LIFE EVENTS BY PSYCHIATRIC PATIENTS AND NORMALS* IGOR GRANT, MARVIN GERST~ and JOEL YAGER$ (Received

28 August 1975)

Abstract-Life event scaling was investigated in 171 male psychiatric patients, a comparison group of 181 “normals”, and 165 relatives of patients and normals. The social readiustment rating auestionnaire (SRRQ) of Holmes and Rahe was employed as the scaling instrument, and a social ieadjustment rating scale (SRRS) was calculated for all groups. Although psychiatric patients and normals agreed on the rank ordering of events, patients generally assigned greater magnitudes to items than did normals. The most significant scaling differences were for items of a marital-family or personal nature. Future research concerning the relationship of life events and psychiatric symptoms should consider employing SRRS weights derived from psychiatric populations rather than existing scores from normative groups. THIS report will be the first of a series describing the results of a three year prospective study into the relationship of life events and psychiatric disturbances in adults. In this paper we will focus specifically on the scaling of life events as measured by the SRRS. The construct validity of this instrument when applied to psychiatric patients, and further information on its reliability in a new group of “normals” will be presented. METHOD Subjects

(a) Psychiatric patient group. The patient group consisted of 171 men consecutively enrolled in the mental health clinic of the V.A. Hospital, San Diego. The study was explained to patients at the time of their first clinic visit and was presented as an effort on the part of mental health workers to understand more clearly factors which might contribute to the improvement or worsening of people’s emotional health. The study was voluntary and required patients to sign informed consents in accordance with V.A. and University of California human subjects regulations. The refusal rate to participate was 31%. Since one of the objectives of the prospective study was to consider the effect of living situation (alone vs with wife or family) on frequency and type of life happenings, an effort was made to enroll approximately equal numbers of “live-alone” and “live with relative” subjects. Because of an overabundance of married patients it was necessary toward the end of the study to accept only consecutive unmarried patients. All patients underwent a diagnostic screening procedure by mental health clinic staff and were assigned diagnoses in accordance with guidelines set forth in the American Psychiatric Association diagnostic and statistical manual (DSM-II). One of us (I. G.) thereafter grouped the patients into one of five general diagnostic categories: affect disorder (N = 43); schizophrenic spectrum (N = 36); alcohol and drug use (N = 29); personality disorder and neurotic conditions (N = 36); and miscellaneous, including transient situational disturbances, organic mental syndromes and undiagnosed conditions (N = 28). The mean age, education, social position and marital status for the patients are summarized in Table 1. (b) Normal control group. An advertisement was circulated among employees at the San Diego Veterans Administration Hospital and the University of California at San Diego inviting their participation as paid volunteers in a study of “how life circumstances affect people’s health”. Subjects were offered $10 for their participation in the initial interview. Not all employees were sent the advertisement. By studying employee registers at the V.A. and U.C.S.D. we attempted to select for invitation only those individuals who seemed likely to match our mental health clinic population in terms *Supported by a grant from the Veterans Administration, MRIS No. 3240. iFrom the Veterans Administration Hospital, San Diego and the Department of Psychiatry, University of California, San Diego. $U.C.L.A. Neuropsychiatric Institute and Brentwood Veterans Administration Hospital. Reprint requests to: Dr. Grant, Psychiatry Service (116-D), Veterans Administration Hospital, 3350 La Jolla Village Drive, San Diego, CA 92161, U.S.A. 141

IGOR GRANT, MARVINGERSTand JOEL YAGER

142

of age, social position, and marital status. Only male employees were invited to participate, and 181 individuals were finally enrolled (Table 1). TABLE1.--DEMOGRAPHICCHARACTEIUSTICS OF CURRENTSAMPLE

PSYCHIATRIC PATIENTS N=171

s.D. =

S.D. = 13.8

SOCIAL POSITION

PI

z=

x = 31.3

fl= 40.0

AGE (YEARS)

RELATIVES OF PATIENTS AND CONTROLS N=165

CONTROLS N=181

x

N

S.D. = 13.6

9.8

I

CLASS I & II

15

0.8

22

12.2

CLASS III

43

25.1

97

53.6

CLASS IV

57

33.3

42

23.2

CLASS V

56

32.7

20

11.0

LIVING SITUATION ALONE b!ITMKELATIVFR (Married, etc,)

37.1

N

%

N

105

61.4

83

45.9

66

38.6

98

54.1

l-

%

N

13.9

23

21.2

35

42

I

25.5

%

(c) Relutive group. Since one of the hypotheses to be tested in the prospective study was that living alone has no effect on the association of life events and symptom formation, the design called for having half of the controls and patients to be married or living steadily with stable girlfriends or blood relatives. Therefore, relatives living with controls and patients were asked to participate in the study. Thirty-four per cent of the potential relative subjects either refused to participate or were not contacted due to objections by the patient or control subject. Seventy-one patient relatives and 94 control relatives were finally admitted to the study. In 94 % of the cases, these relatives were wives of controls while the other 6 % consisted of other blood relatives, in-laws, or stable girlfriend, while 73 % of the patient relatives were wives, 9 ‘4 were stable girlfriends, and 18 % were other blood relatives. Instruments

All subjects underwent initial structured psychiatric interviews andcompleteda number of questionnaires. Since this report specifically concerns life change scaling, we will describe only those instruments which contributed to this issue. (1) Social readjustment rating questionnaire (SRRQ). This paper and pencil test consists of a list of 43 life happenings to which subjects are asked to assign weights using an open ended scaling procedure with the “marriage” item arbitrarily assigned a weight of 500 as an anchor point. From population responses to the SRRQ, a mean weighted score is derived for each item, and the weighted items compose the Social Readjustment Rating Scale (SRRS). These SRRS item scores are derived from the SRRQ by dividing each item’s arithmetic mean for each group by 10, and rounding off the result to the nearest whole number. This procedure has been used previously by Holmes et al. [l, 21 to simplify computational tasks and to confine scores to the lo-100 range. The instructions given to subjects were identical to those published by Holmes and Rahe [l]. (2) Symptom checklist (SCL).* This is an inventory of 67 symptoms commonly associated with psychiatric illness. The items are in the form of statements concerning various somatic, interpersonal, cognitive, affective, behavioral and drug/alcohol usage phenomena. A subject is required to indicate whether in the past 2 months, a symptom has not occurred, occurred less than once a month, several *The SCL is available from the authors on request.

Scaling of life events by psychiatric patients and normals

143

times a month, several times a week, or daily. An SCL score was computed for each subject by assigning weights of 0, 1, 2, 3, or 4 for each of the frequency designations and summing symptom reports. This score was used to provide an index of psychiatric distress.

RESULTS Demographic

characteristics of subjects

The age, socioeconomic status (S.E.S.) and living situation (alone or with relative) of our sample are summarized in Table 1. Patients were found to be older (40.0 vs 31.3 yr; t = 6.83, p < OGll) of lower social class (e.g. 32.7% vs 11.0% in class V; x 2 = 41.2, p < OGN) and more often isolates (61.4% vs 46.1%; X* = 8.24, p < 0405) than the control sample. Influence of demographiccharacteristics on life event scaling Since our patient and control samples differed in their age, S.E.S. and living situation, we explored the possibility that any variations in SRRS scores might be attributable to these differences. We first examined these possible influences by dividing our total sample (n = 517) into 3 age groups (under 30; 30-50; and over 50), two social position groups (high group = Hollingshead class I, II, III; low group = Hollingshead class IV, V) and into males and females. The rank order correlations of SRRS scores were: between age groups r = 0.92,0.89, and 0.92 (p < 0G)l);between the two social position groups, r = 0.95 (p < 0.001); and for the two sexes, r = 0.93 (p < 0.001). While these rank orderings are virtually identical, mean differences of items and the influence of variable combinations are not accounted for in this procedure. For these reasons each of the 43 SRRS items were subjected to a 3 way analysis of variance (fixed constants model) using groups (control, patient) S.E.S. (high, low) and age (< 30, 30-50, > 50) as the independent factors. Sex was not included as an independent variable and will be discussed below. Of the 43 item analyses, significant main effects for groups (control, patient) appeared in 15 items, for S.E.S. in 4 items, and for age in none of the items. Two way interactions revealed significant group X age influences for 1 item, group X S.E.S. influences for 2 items and age X S.E.S. influences for 2 items. Two items also were involved in the 3 way interaction. From these analyses it can be reasonably concluded that variability in SRRS item scores is substantially associated with controlpatient differences. However, age and S.E.S., in the present sample, are minimal influences. It is possible that sex differences might account for substantial SRRS item variability. Sex differences however, were not tested in the above analyses since sex and the patienthood variable are very highly correlated: all patients and controls are male and virtually all relatives are female. Therefore, testing sex differences would simply replicate patient-control differences. This problem, however, was approached indirectly by assessing the comparability of the two relative samples (spouses of controls and of patients) and their relationship to control subjects (males). Pairwise t tests for each of the 43 SRRS items between control spouses and patient spouses revealed only one significant difference (2-3 differences can be expected by chance). Comparisons between male controls and all female spouses revealed differences in 5 of 43 items. Thus, it would appear that sex differences, like age and S.E.S. are not systematically related to SRRS scores in our sample. Reliability of life event scaling

Table 2 presents Social Readjustment Rating Scale (SRRS) scores using the responses provided by each group of subjects (patients, controls, relatives, and total sample) and their rank ordering of items.* If it is correct that life event scaling has wide applicability, the relative ranking of events in terms of amount of readjustment required should be similar across populations. In order to test this assumption we selected the 25 items which are common to the SRRS version which we employed and the original SRRS [I], and compared the rank order of items by our normal controls (n= 181) with the original sample (n = 394). The rank order correlation was highly significant (Spearman r = 0.91,p < O+Ol). We also compared our patient and patient relative sample (n = 242) with a similar sample (n = 373) tested by Paykel et al. [17]. Although our SRRQ and Paykel’s life event list differ substantially in instructions and wording of items, there are 14 common events in each questionnaire. The rank order correlation, though less powerful was again very reliable statistically (Spearman r = 0.70, p < 0.01). Thus, it appears that the ranking of stressfulness of life events by our sample is very similar to the results obtained in two previous studies. *SRRQ arithmetic authors.

item means, standard deviations and geometric means are available from the

144

IGORGRANT,MARVINGERST

and JOEL YAGER

TABLE l.-SOCIAL READJUSTMENT RATING SCALE (SRRS): ITEM RANKINGS OF CONTROL AND PATIENT GROUPSANDCOMPARISONSWITHOTHERSTUDIES TOTAL SAMPLE (N=517)

+ DEATH OF A SPOUSE DIVORCE +*DEATH OF A CLOSE FAM. MEMBER +*MARITAL SEPARATION OUT OF WORK MAJOR INJURY OR ILLNESS DEATH OF A'CLOSE FRIEND PURCHASE OF MORE THAN $10.000 FINANCIAL DIFFICULTIES' ' FIRED OR SUSPEND FROM SCHOOL DETENTION IN JAIL BIRTH OR ADOPTION OF CHILD +*SFXUAL DIFFICULTIES MARRIAGE *DFCISION REGARDING FUTURE RETIRFmNT CHANGE IN HEALTH OF FAM. MEMBER RELATIVES MOVE IN +*CAANGE IN # ARGUMENTS CHANGING NORK THREATENED LEGAL ACTION +*SEPARATION FROM SPOUSE DUE TO NORK TROUBLES W/CO-WORKERS ENGAGEMENT +*CHANGE IN PELIG. OR POLIT. CONVICTIONS +*IN-LAW TROUBLES PURCHASE OF LESS THAN slO,OOO LIFE OR WORK GOING ESP. WELL + CHANGE IN WORK RESPONSIBILI'I-Y CHANGE IN LIVING CONDITIONS TROUBLES WITH BOSS CHANGE IN WORKING HOURS +*WIFE BEGINNING OR CEASING WORK CHANGE IN PHYSICAL WORK +*REVISION OF PERSONAL HABITS +*CHANGE IN RESIDENCE + STUDY AT HOME VACATION +*CFANGE IN # FAM. GET-TOGETHERS +*CHANGE IN SLEEPING HABITS +*CtlANGE IN EATING HABITS CHANGE IN # FRIENDS GET-TOGETHERS +*MINOR VIOLATIONS OF THE LAN

ITEM RANK 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43

PATIENTS (N=171)

MEAN VALUE 114 92

85 77 65 63 58 56 56 54 54 53 52 50 49 45 44 44 40 39 38

37 36 34 32 31 30 29 29 29 29 28 28 27 25 24 24 22 22 21 21 20 17

ITEM RANK 1 3 2 4 6 5 10 7 8 13 il 18 9 19 1L 14 21 25 16 15 23 22 17 24 20 26 39 30 27 29 35 36 32 28 34 33 31 40 37 38 42 41 43

MEAN VALUE 125 105 106 94 83 83 bi! 74 73 61 64 51 71 50 62 55 47 41 51 53 46 46 51 45 50 40 29 37 39 38 31 30 32 39 31 31 34 29 29 29 27 27 21

PATIENT VS CONTROLS * PC.05 + Subgroup differences (p <.05)

Comparisons of psychiatric patients and controls As will be seen from Table 2, the rank order of events by psychiatric patients is virtually identical to control ranking (Spearman r = 0.96,~ < 0.001). At the same time inspection of the actual weights which various groups assigned to each item revealed that psychiatric patients consistently attached a greater magnitude to life events than did controls (42 of 43 items, p < 00X). Inspection of SRRS sum scores (obtained by adding the 43 item weights for each subject) of patients and controls confirms the tendency of patients to magnify (mean patient SRRS score = 223.27 vs 154.52 for controls; p < OXiOl). As a specific example, patients and controls both list “marital separation” as the fourth ranked event in stressfulness. However, patients perceived this event as nearly 35% more stressful than did controls (control item score = 62; patient item score = 94).

Scaling of life events by psychiatric patients and normals TABLE

2

(cont’d).-SOCIAL

READJUSTMENT

PATIENT GROUPS

AND

RATING

SCALE

COMPARISON

(SRRS): ITEM RANKING

WITH

(N=l81)

PAYKEL RELATIVES

HOLMES & RAHE(1) NORMALS

(N=165)

(N=394) ITEM

RANK

f 2

4 5 n 6 13 11 7 12 9 1s 10 14 18 16 17 23 19 20 24 27 21 34 30 22 26 33 29 25 28 32 31 35 37 41 36 42 39 38 40 43

MEAN VALUE 99 75 77 62 G2 54 62 44 49 57 46 50 41 50 41 38 39 39 31 35 32 31 28 32 22 24 32 29 22 24 30 26 22 22 22 20 17 21 16 17 18 17 14

OF CONTROLS

ITEM RANK 1 2 4 3 11 9 17 8 13 16 6 5 14 10 15 18 12 7 19 33 20 21 25 31 29 22 23 34 27 30 28 26 24 38 35 32 36 43 2: 2: 42

MEAN VALUE 119 97

72 75 49 50 43 51 46 44 52 59 45 50 45 41 46 52 38 23 36 34 29 24 26 31 30 22 27 26 26 28 29 20 22 23 21 16 20 18 20 17 16

ITEM RANK 1 2 5 3

AND

OTHER STUDENTS

NORMAL CONTROLS

145

(3

PATIENTS

) &

RELATIVES

(N=373)

MEAN VALUE 100 73 63 65

ITEM RANK 2 10

4 11

6 17

53 37

8 4

47 63

18 16 28 6 8 3

13 7

39 50

52

10 11

45 44

19 18

35 36

MEAN VALUE SCALING NOT COMPARABLE

37 59 24

29

22

29

30

23

26

26

29 32

24 20

41 39 38 40

13 15 16 15

43

11

38

The item analyses of variance, as previously discussed, revealed 15 control vs patient SRRS differences unconfounded by demographic influences (see items with asterisks in Table 2). Most differences appear to occur in events relating to marital-family changes or to personal health changes (10 of 15 items). Items referring to work, finances, or legal matters do not differentiate patients and controls (1 of 15 items). The remainder fall in the miscellaneous category.

Comparisons of patient subgroups and controls In order to determine whether patients in specific diagnostic categories differ in perception of events, we divided this group into five diagnostic groups (affect disorder; schizophrenic spectrum; character disorder and neurotic spectrum; alcohol and drug user; and other unclassified or mis-

146

IGOR GRANT, MARVINGERSTand JOEL YAGER

cellaneous conditions) and compared the mean SRRS weights assigned by each group with all other groups and with controls on an item by item basis. Seventeen items revealed an overall difference (one way analyses of variance) and are noted in Table 2 by plusses. The number of significantly different items for each pair of groups is presented in Table 3. The largest number of differences is between the control group and the three patient TABLE3.-SRRS

ITEMSSUBGROUPS DIFFERENCES

co

CH

s

A

0

ETOll

. (CC)

CONTROL

< (A)

12*

6)

14

2

(Cl11

13

4

(ETOH) 1

2

1 0

1

I

I

AFFECT DISORDERS

SCHIZOPHRENIAS

CHAMCTER

DISORDERS

ALCOHOL & DRUGS

I OTHERS

(0) I

4l0I0131~I

4 3

1 I

1

1

I I

I

I

4

I

groups of affect disorder, schizophrenia, and character problems; in each case the patient groups assigned greater magnitude to events than did controls. There were relatively few differences between “alcohol and drug” and “other” patients and controls. There were also few differences among the five patient groups. Event experience and SRRS ratings Horowitz et al. [4] have reported that persons who have experienced certain events subsequently rate events as requiring less readjustment than persons who have not. Such events were in the classes of “moderate threats to self” and “threats to material well being”. For a few other items (“important separations”) the prior experiences of that event led to subsequent assignment of higher weights. In an effort to replicate these observations we divided our sample into “experienced”and “inexperienced” groups. Experienced subjects were those who reported occurrence of an event in the previous two months. We then compared the mean weights attached to each item by experienced and inexperienced subjects. For patients, 41 items were employed and for controls 39 items since some items had one or less persons in the experienced cell. The number of statistical differences expected by chance were calculated (i.e. 5 % of the total) for each set of items, and x2 computed. Neither patients nor controls revealed non-chance departures for experienced and non-experienced items. Since the hypothesis failed this more stringent statistical test, the less powerful sign test was employed (i.e. number of experienced or non-experienced items with higher scores regardless of statistical significance). Again x* computed for both the control and patient samples were not significant. Horowitz et al. also found that experiencing a life event leads to greater similarity of perception in weighting the stressfulness of the event than among persons who are inexperienced (i.e. variance of SRRS items is smaller for experienced vs inexperienced subjects). This hypothesis was tested in the present study by computing the statistical significance (F ratio) of variances for experienced vs inexperienced patients and controls separately for each SRRS item. For controls, inexperienced persons had greater variability in perception of events than experienced persons (20 of 39 items; x2 = 381,~ < 0.001). For patients the situation was more complex. While the overall x2 is statistically significant (x2 = 335, p < O.OOl), departures from expected frequencies occur in both the experienced and non-experienced directions. For 10 items, previous experience led to greater variability, while for 17 items lack of experience led to greater variability. Thus for control subjects experiencing an event leads to greater predictability of SRRS scores, while for patients no prediction can be made.

Scaling of life events by psychiatric patients and normals

147

DISCUSSION

Clinical belief and some experimental findings hold that persons with psychiatric problems generally perceive their environment as more difficult with which to cope. For example, Beck [5] has observed cognitive distortions in depressed patients involving pessimistic magnification of otherwise neutral circumstances. Shapiro [6] has noted that persons with hysterical character styles perceive their environments in extremes, i.e. all good or all bad. MacPhillamy and Lewinsohn [7] have found that depressed subjects rate various events as significantly less “pleasant” than nondepressed subjects; and Cochrane and Robertson [S], in developing their Life Events Inventory, also noted that their psychiatric patients tended to assign generally higher weights across all items. Theorell [9] also suggests that “neurosis patients” tend to rate various events as requiring more “adjustments” and causing more “upsettingness” than do normal controls. In this regard, our finding that psychiatric patients as a group magnify the perceived readjustment required to cope with most life happenings as measured by the SRRS is of considerable interest. In particular, events which patients perceive as most stress inducing concern changes in family relationships and personal health. Events relating to work, finances and legal matters are not differentially stressful for patients and normals. This “magnification” of life happenings by the present patient sample suggests that future life event research with psychiatric subjects should employ population specific event weights rather than existing norms. Such a strategy might increase the likelihood of uncovering event-symptom associations which might otherwise be obscured. A further refinement of this approach might employ the use of individual SRRS weights rather than any group norm. This method has been suggested by Rahe [IO] and by Vinokur and Selzer [ll]. In future work we plan to test the relative efficacy of each of these methods. We also expected that different classes of events might be more difficult for some diagnostic groups than for others within the patient sample. However, we were not able to find differences in weighting of events among patients with affect disorders, schizophrenic spectrum conditions, or character disorders. We suspect that small subgroup size and the considerable variability in patient ratings has contributed to the apparent homogeneity of our patient population. The relative imprecision of diagnostic criteria based on DSM-II must also be regarded as a confounding influence, Event weighting of alcoholic patients was also extremely variable but placed them between normals and other patients in terms of tendency of magnify. Our other findings largely confirm previous observations regarding the SRRS. For example, the rank ordering of events by our control normals correlates highly with that reported by Holmes and Rahe. Similarly, for a group of patients studied by Paykel and our present patient sample, rank ordering of common life event items were highly correlated. Thus, the frequently noted similarity of perception of life events among various subject groups was confirmed in our findings. This study also confirmed previous findings [12] that age, sex and social position do not appreciably account for differences among SRRS scores. On the other hand, Myers et al. [13] found a higher occurrence of “high-impact events of an undesirable nature” among lower class persons. In a future report we intend to examine more closely the relationship of event perception, event occurrence, symptom formation, and social position over time.

IGOR GRANT, MARVIN GERST and JOELYAGER

148

We also considered whether having experienced a particular event influenced the subsequent perception of similar events. For example, theories of adaptation [14] and of clinical behavior change [15] include the interaction with environmental events as necessary elements in the re-learning process. In the present study we found no differences in SRRS magnitude estimations of experienced vs non-experienced events. This is contradictory to the findings of Horowitz [4] who did note such differences for at least some events. It should be borne in mind, however, that in studies employing a large number of discrete questionnaire items (such as the 43 item SRRQ) a sampling theory approach to statistical tests should be employed. Chance occurrence alone would predict the appearance of a certain number of significant differences. This might have been the case in the study by Horowitz et al. Even though mean differences of experienced vs non-experienced events did not occur, it is possible that variability of event perception in relation to prior experience would change. The findings here are more complicated. While controls did rate more non-experienced items with greater variability, this was not the case for psychiatric patients. Psychiatric subjects perceived several non-experienced and experienced events in more variable fashion. This further leads us to conclude that life happening perception by a group of psychiatric patients is atypical when compared to normals, again suggesting the likelihood that group specific readjustment weights might be more appropriate than existing norms as tools in research involving the interaction of life events and psychiatric illness. REFERENCES 1. HOLMEST. H. and RAHE R. H. The social readjustment rating scale. J. Psychosom. Res. 11, 213 (1967). 2. MASUDA M. and HOLMEST. H. Magnitude estimations of social readjustments. J. Psychosom. Res. 11, 219 (1967). 3. PAYKEL E. S., PRUSOFFB. A. and UHLENHU~HE. H. Scaling of life events. Arch. Gen. Psychiat.

25, 340 (1971). 4. HOROWITZ M. J., SCHAEFERC. and COONEY P. Life event scaling for recency of experience. In Life Stress and Ilness (Eds. GUNDERSONE. K. E. and RAHE R. H.), Springfield, III. Thomas. pp, 125-133 (1974). 5. BECKA. T. Depression: Clinical, Experimental and Theoretical Aspects. Hoeber, New York (1967). 6. SHAPIROD. Neurotic Styles. Basic Books, New York (1965). 7. MACPHILLAMYD. J. and LEWINWHN P. M. Depression as a function of levels of desired and obtained pleasure. J. Abnorm. Psycho/. 83, 651 (1974).

8. COCHRANER. C. and ROBERTSONA. The life events inventory: a measure of the relative severity of psychosocial stresses. J. Psychosom. Res. 17, 135 (1973). 9. THEORELLT. Life events before and after the onset of a premature myocardial infarction. In Stressful Life Events, DOHRENWENDB. S. and DOHRENWENDB. P. Wiley, New York pp. lOl117 (1974). 10. RAHE R. H. The pathway between subjects’ recent life changes and their near-future illness reports: representative results and methodological issues. In Stressful Life Events, DOHRENWENDB. S. and DOHRENWENDB. P., Wiley, New York pp. 73-86. (1974). 11. VINOKURA. and SELZERM. I. Life events, stress and mental distress. Proceedings, 8lst Annual

Convention APA, 329-330 (1973). 12. RAHE R. H. Multi-cultural correlations of life change scaling: America, Japan, Denmark and Sweden. J. Psychosom. Res. 13, 191 (1969). 13. MYERSJ. K., LINDENTHALJ. J. and PEPPERM. Social class, life events, and psychiatric symptoms. In Stressful Life Events, DOHRENWENDB. S. and DOHRWENDB. P., Wiley, New York pp. 191205 (1974).

Scaling of life events by psychiatric patients and normals 14.

COELHO G.

V., HAMBURG D. A. and New York (1974).

15.

BANDURA A.

ADAMS

149

J. E. (Ed%) Coping and Adaptation. Basic Books,

Principles of Behavior Modification. Holt, Rinehart & Winston, New York (1969).