First-Episode Major Depressive and Dysthymic Disorder in Childhood: Clinical and Sociodemographic Factors in Recovery

First-Episode Major Depressive and Dysthymic Disorder in. Childhood: Clinical and Sociodemographic Factors in Recovery MARIA KOVACS, PH.D., D. SCOTT OBROSKY, M.S., CONSTANTINE GATSONIS, PH.D., AND CHERYL RICHARDS, M.B.A.

ABSTRACT Objective: To characterize the temporal pattern of depressive disorder in childhood, the first episode of depression was examined, focusing on recovery and its baseline predictors. Method: The sample includes 112 clinically referred 8- to 13-year-olds with first-episode major depressive or dysthymic disorder participating in a naturalistic follow-up study. Psychiatric diagnoses were based on standardized interviews and operational criteria. Recovery was modeled by multivariate procedures using baseline clinical and demographic predictors. Results: Recovery rates were 86% and 7% for major depression and dysthymia, respectively, 2 years after onset. Median duration of major depression was 9 months and was predicted only by underlying dysthymia. Median duration of dysthymic disorder was 3.9 years and was predicted only by comorbid externalizing disorder. In post hoc analyses, no positive treatment effects were detected. Conclusions: First-episode depression in youths is persistent, it generally appears to run its own course, and its naturalistic treatment requires scrutiny. However, because comorbid externalizing disorder apparently affects duration of dysthymia, intervention for behavior problems may shorten this type of depression. J. Am. Acad. Child Adolesc.

Psychiatry, 1997, 36(6):777-784. Key Words: depressive disorders, temporal course, recovery, predictors, childhoodonset psychopathology

Accepted january 10, 199% Dr. Kovacs, Mr. Obrosky, and Ms. Richards are with the Department of Psychiatry, University ofPittsburghScbool ofMedicine, and Western Psychiatric Institute and Clinic, Pittsburgh. Dr. Gatsonis is with the Centerfor Statistical Science, Brown University, Providence, RI. This study w a supported by NIMH grant MH33990. Correspondence to Dr. Kovacs, WPIC, 381 1 O'Hara Street, Pittsburgh PA 15213. 0890-8567/97/3606-0777$03.00/00 1997 by the American Academy of Child and Adolescent Psychiatry.

patterns and correlates of onset and recovery. This supposition is consistent with findings that the episode number itself may prognosticate outcome in depression, with multiple episodes typically predicting worse prognosis at a given admission (Greenhouse et al., 1987; Gonzales et al., 1985; Keller et al., 1982, 1983). The rate of recovery is one course feature of depressive disorder that has been examined in clinical samples, although episode number has generally not been considered. Duration of depression in adults has been associated with various characteristics such as comorbid psychiatric disorder, severity and age at onset of the depressive episode, and family income or family composition (Akiskal, 1982; Keller et al., 1986, 1992; McLeod et al., 1992). Episode duration in youths also has been studied as a function of psychiatric comorbidity, psychoticism, age at onset, sex, or family background, among others (Keller et al., 1988; Lewinsohn et al., 1994; McCauley et al., 1993; Strober et al., 1993). Some characteristics, such as having an underlying dysthymic disorder, typically predict length of major

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The course of depressive disorder starting with the earliest episode has not been well characterized, partly because first-episode cases are in the minority among clinically referred adults (Brodaty et al., 1991; Keller et al., 1992; Rush et al., 1995). However, by focusing on depressed juveniles, we can study the vicissitudes of affective illness from its initial stage (Kovacs, 1996). Episode-specific characterization of depressive disorder should be particularly informative. Post (1992) has proposed, for example, that the first bout of affective illness sensitizes individuals to future episodes. Therefore, initial and subsequent episodes should differ in

K O V A C S ET AL

depression in adults, whereas no clinical variable has yet been consistently shown to predict episode length in youths. In addition, almost all published data concern major depressive disorder rather than dysthymic disorder, and findings are rarely presented by episode number. Finally, although there has been increased interest in baseline clinical prognosticators of outcome (Greenhouse et al., 1987), such information about depressed youths is still scant. To characterize the temporal course of very earlyonset affective illness, we focus in this article on the first depressive episode of clinically referred and prospectively observed children and integrate our results with recent reports in this area (Lewinsohn et al., 1993, 1994; McCauley et al., 1993). Once a critical mass of information becomes available on first-episode depression in youths, inconsistencies in findings should be easier to resolve. Studying subsequent episodes thereafter will help build a comprehensive knowledge base about course and outcome of childhood-onset affective illness. For this article, two issues were addressed: (1) rates of recovery from onset for first-episode major depressive disorder and dysthymic disorder and (2) whether recov. . ery is predicted by clinical and background characteristics that can be ascertained at initial referral and early in the course of the disorder. Multivariate statistical procedureswere used examine the effects of predictor On recovery, including ‘Omorbid disorder as well as conduct, oppositional, or attention deficit (i.e., externalizing) disorder, age at onset of depression, co-occurrence of major depression and dysthymia, the child’s caregiver arrangement, sex, race, and socioeconomic status (SES). Apart from our multivariate procedures, we also examined the effects on recovery of several variables of clinical and empiric interest, including treatment. For children with major depression, we considered whether episode subtype (psychotic or melancholic) or their birth cohort (Kovacs and Gatsonis, 1994) was associated with rate of recovery. The present article differs in several regards from previous reports of this study on the index episode of major depression and dysthymia (Kovacs et al., 1984, 1988, 1989); namely, the sample is larger, all cases with first-episode depression at study entry are included, and the observation interval is longer. In addition, we used multivariate analytic approaches to model recovery

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from depression that take into account possible relationships among the predictor variables.

METHOD Design Subjects were recruited primarily through the child psychiatry outpatient service of the University of Pittsburgh and the general medical clinic of the Children’s Hospital of Pittsburgh. These sites contributed, respectively, 82% and 16% of the sample in this article. A few cases were recruited through other avenues, as described elsewhere (Kovacs et al., 1984). We systematically screened consecutive cases who presented to our primary recruitment sites for a variety of reasons, and thus study participation was not determined by referral reason or the service provider‘s diagnosis. Each child had to meet the following demographic criteria for study participation: 8 to 13 years old, not mentally retarded, no major systemic medical illness, ambulatory psychiatric and medical status, and lives with parent(s) or legal guardian(s) within commuting distance of greater Pittsburgh. Signed consents were obtained for an initial 5-year follow-up, and then for optional subsequent follow-up periods. Families received monetary reimbursement at each assessment. The protocol stipulated three postintake assessments in the first year of participation and semiannual assessments in subsequent years. Follow-up was naturalistic because treatment was not controlled by the present investigators. The first 6 months after study entry constituted a phase of diagnostic verification of the index o r primary research diagnosis.

Assessment and Diagnosis Psychiatric diagnoses were based on evaluations with the semistructured, symptom-based Interview Schedule for Children and Adolescents and its addenda (ISCA), which have good to excellent symptomatic interrater reliability (Kovacs, 1985). At each assessment, the ISCA was administered by the same clinician separately to the parent about the child and to the child about himself 0-r herself. The clinicians were extensively trained master’s- or Ph.D.level mental health professionals. The research clinicians, who were aware of the outcome of previous assessments, reviewed results of each interview on multiple occasions. Only symptoms indicative of distress or functional impairment at predefined levels of severity counted toward a diagnosis. Three aspects of our diagnostic procedures should be highlighted: (1) irrespective of the depression, if the history and presentation indicated other disorders, all pertinent diagnoses were assigned; (2) we developed standardized procedures for diagnosing concurrent disorders with overlapping symptoms (Kovacs et al., 1984); and (3) even if it was protracted, a partially remitted episode of major depressive disorder was never diagnosed as dysthymia. Based on ISCA symptoms and clinical history, final DSM-ZII (American Psychiatric Association, 1980) diagnoses were assigned by consensus among the research clinicians. This procedure has been shown to have face and predictive validity (Kovacs et al., 1984, 1994; Last et al., 1987; Strauss et al., 1988). In addition, structured data sheets were completed with parents to record anamnestic, demographic, and treatment information, and treatment was verified through providers’ records.

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FIRST-EPISODE DEPRESSION

Definition of Onset and Recoverv Onset and offset dates of disorders were typically based on parental report because adults are better historians than children. Onset of a disorder was when, according to the interview data, all criterion symptoms were present for a given syndrome. Offset, or recovery, was defined as no more than one clinically significant symptom and few if any subclinical symptoms remaining of the pertinent syndrome, and maintenance of the foregoing state for a minimum interval of 2 months. After a patient remained asymptomatic for the required 2 months, the offset or recovery date of the given episode was set at the beginning of that interval. If major depression was superimposed on dysthymic disorder, we offset the major depression when the child no longer had those depressive symptoms by virtue of which he or she initially met criteria for it, although the baseline dysthymia could be present. In some instances, the offset date of an episode did not meet the 2-month asymptomatic criterion because the disorder turned into a different condition. For example, if the major depressive disorder directly converted to an episode of mania, the date of “switch” was operationally defined as the offset of the index depression. T o assist temporal recall, informants drew a time line and indicated the period of the disorder in relationship to marker events (e.g., holidays, birthdays). If an onset or offset date was unclear, a calendar interval was delimited during which the symptoms emerged or remitted, respectively (e.g., “between Christmas and Easter”). T h e date in question was then operationally set at the midpoint of that interval. Onset and offset dates also were consensually assigned by the research clinicians.

Cohort W e report o n 112 children with first-episode major depressive disorder ( M D D ) or dysthymic disorder ( D D ) as the index (initial) diagnosis: 57 children with M D D , 32 with M D D superimposed on dysthymic disorder ( M D D / D D ) , and 2 3 with D D , representing 97.4% (1 12/115) of all study cases with these intake classifications. Three youths with index M D D were considered as probably in their first episode, although this could not be definitely established owing to changes in caregivers. T w o children from the M D D / D D group are included in the analyses of D D , but not of M D D , because their index M D D s were second episodes. Youths entered the study between 1378 and 1387, and follow-up interviews up to September 1, 1330, were examined. T h e demographic characteristics of the 112 children were similar to those reported for smaller portions of our study group (Kovacs et al., 1384, 1983). There were 6 2 girls and 50 boys; the group was 65.2% white, 32.1% black, and 2.7% biracial; at study entry, the mean age was 11.27 years (SD 1.57 years; range, 8.0 to 13.3 years); 27.7% lived in intact families and 53.6% lived in twoparent households. By Hollingshead’s T w o Factor Index of Social Position (Hollingshead, 1357),head ofhousehold’s SES was distributed as follows: 2.7% in category I (highest), 5.4% in category 11, 22.3% in category 111, 40.2% in category IV, and 23.5% in category V (lowest). For statistical analyses, race was dichotomized as white versus nonwhite, and SES was dichotomized as higher (categories I, 11, 111) versus lower (categories IV, V). Altogether, 54 youths (48.2%) had comorbid anxiety disorder and 31 (27.7%) had comorbid externalizing disorder as defined below. Major Depressive Disorder Group. Altogether 8 7 children had first-episode M D D as an index diagnosis (30 had concurrent DD and are also included among the dysthymic cases). T h e group was 42.5% male, 63.2% white, and 66.7% lower SES; 29% lived in

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intact families. Median time between onset of index M D D and study entry was 1 7 weeks. Dysthymic Disorder Group. Altogether 55 children had firstepisode DD as an index diagnosis (30 also had superimposed firstepisode major depression at entry). This group was 49% male, 69% white, and 71% lower SES; 26% lived in intact families. Median duration of dysthymia at study entry was 2 years. Note that DSM-III requires 1 year of symptoms for a DD diagnosis.

Dependent and Predictor Variables T h e dependent variable was time to recovery or duration of first-episode M D D o r D D . T h e sociodemographic predictor variables were sex, race, SES, and family arrangement at study entry (two-parent household, yes versus no). Comorbidity was defined as presence of the specified nonaffective disorder anytime during the episode of depression up to and including study entry. Recovery from M D D was examined as a function of the following baseline clinical variables: comorbid anxiety disorder, comorbid attention deficit/conducr/oppositional, that is “externalizing” disorder, underlying D D , and age at onset of M D D . W e considered separately having received pharmacotherapy and/or psychotherapy during the episode, whether the episode was psychotic/melancholic, and birth cohort (Kovacs and Gatsonis, 1994). Recovery from D D was examined as a function of the following baseline clinical variables: comorbid anxiety disorder, comorbid externalizing disorder, superimposed episode of M D D , and age at onset of D D . W e considered separately having received psychotherapy during the index episode. None of the DD cases received pharmacotherapy for D D . Birth cohort did not appear to affect age at onset of DD (Kovacs, 1334, unpublished data) and was not considered.

Statistical Methods Recovery from depression was examined using survival-analytic techniques that accommodate censored observations (Kalbfleish and Prentice, 1980). In a longitudinal study, censored observations refer to subjects who drop out before the outcome of interest (in this case, recovery) occurs or have not experienced the outcome by the last observation. By taking into account all information o n all cases, survival-analytic techniques provide a distribution of the time to response (recovery) for the cohort. The cumulative probability of recovery from first-episode depression was computed via the Kaplan-Meier estimator (Kalbfleish and Prentice, 1980). Alternatively, the data were organized into time intervals (life tables) for ease of presentation. T h e relationship of covariates and time to recovery was assessed via Cox’s regression analytes, also known as proportional-hazards models (Kalbfleish and Prentice, 1980). These models yield for each covariate an estimate of the regression coefficient and its standard error. A positive coefficient indicates that higher values of the covariate are associated with an increased hazard rate and a shorter time to recovery. W e used a stepwise forward-selection to retain a procedure, with p < .05 for the improvement in covariate in the model. Meaningful interactions between the retained covariates were examined. For discrete covariates in the model, results were cross-validated via the log-rank test. T h e assumption of proportional hazards was checked for all significant covariates by plotting the survival functions for the levels of each covariate and was found to be approximately true. Diagnostic checking also was done o n the residuals of the final models. Most covariates were fixed; in other words, their value

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did not change with rime (e.g., sex, preexisting/comorbid disorder). However, having received antidepressant medication during the MDD episode also was examined as a time-dependent covariate.

RESULTS First-Episode Major Depressive Disorder

Characteristics. Age at onset of first M D D ranged from 7.75 to 14.01 years (mean = 10.98, SD 1.57); the upper bound (which exceeds the study entry age cutoff) reflects that a 6-month phase was provided after intake for diagnostic verification and that in a few cases, the presence of all criterion symptoms was established only at follow-up. At initial presentation, 30 patients (34.5%) had underlying DD, 44 (50.6%) had anxiety disorder, and 2 3 (26.4%) had externalizing disorder. During the depression, 6.9% of the cases met criteria for psychotic subtype and an additional 8.0% met criteria for melancholic subtype. Recove ry. Seventy-nine children had recovered from their M D D . Eight cases were censored: one had not recovered and seven discontinued study participation before recovery. Table 1 presents numerically the cumulative probability of recovery from M D D by 3-month intervals, as well as the hazard ratio (and its standard error) for each interval. The hazard function suggests that recovery from M D D was most likely during the TABLE 1 Probability of Recovery From Onset in First-Episode Major Depressive Disorder

Interval From Onset (mo)

0-3 3-6 6-9 9-12 12-15 15-18 18-2 1 2 1-24 24-27 27-30 30-33 33-36 36-39

n at Start of Interval

87 80

56 41 25 18 14 13 10 9 7 6 4

-

-

75-78

1

780

Hazard Function (SE)

.03 .10 .09 .16 .09 .08

.02 .06 .04 .08

.05 .13

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(.01)

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(.02) (.02) (.04) (.04) (.04) (.02) (.04) (.04) (.06) (.05) (.09)

.08

(.OO)

-

.oo

Cumdative Probability of Recovery at Start of Interval

(.00)

.33 .49 .69 .76 32 .83 .86 37 .90 .9 1 .94 -

.99

3rd to 12th month after onset, with a peak during months 9 through 12. The estimated median recovery time was 9.01 months (SE = 0.65); the cumulative probability of recovery was .69 (SE = .051) by 1 year, .94 (SE = .027) by 3 years, and .99 (SE = .014) by 6 years from onset. If a chronic episode is defined as longer than 18 months, then an estimated 18.4% of these youths had a chronic first major depression. Predictors of Recovery. From among the four sociodemographic and four clinical variables that were considered, underlying dysthymia was the only variable that entered the Cox model in a stepwise procedure (regression coefficient = .737, SE = .257, = 7.73, df = 1, p = .0054). Age at onset of M D D had no notable effect on recovery ( p = .1265). Median duration of M D D was 9.94 months (SE = 0.84) for children who did not have DD and 6.73 months (SE = 1.36) for children with dysthymia (log-rank = 8.61, df = 1, p = .0033). Figure 1 depicts the Kaplan-Meier functions for these two groups. In separate analyses, no significant differences in recovery rates were detected for children with psychotic/ melancholic depression subtype versus the rest of the youths (x' = 0.04, df = 1, p = .8417) or by birth cohort (trichotomized) = 1.12, df = 2, p = .5707) when added to the model with DD. Treatment and Recovery. Because we did not control the nature, timing, or duration of treatment, the relevant analyses must be regarded with caution. Altogether 65.5% of the cases received psychological treatment and 16 (18.4%) received antidepressant medication

x2

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Time From Onset (in months)

Fig. 1 Cumulative probability of recovery from onset in first-episode major depressive disorder (MDD) as a function of underlying dysthymic disorder (DD).

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FIRST-EPISODE DEPRESSION

(mostly tricyclics) during the MDD episode (the remainder had assessment interviews but no treatment). To parallel previous analyses (Kovacs et al., 1984), we considered antidepressant medication as a discrete covariate (yes versus no) and found that it was associated with more protracted recovery when added to the model with DD (coefficient = - 1.09, SE = .325, = 13.53, df= 1, p = .0002). As a time-dependent covariate (using the starting and ending dates of medications prescribed during the index episode), antidepressant pharmacotherapy still was associated with longer time to recovery from M D D when added to the model with DD (coefficient = - 1.4029, SE = .7268, = 5.82, df= 1 , p = .0159). Having received psychotherapy during the episode was considered as a discrete covariate (yes versus no) because precise starting and ending dates were not readily available. When added to the model with D D , psychosocial intervention also was associated with more protracted recovery from major depression (regression coefficient = -.6544, SE = .2428, = 6.91, df = 1, p = .0086).

x2

x2

x2

First-Episode Dysthymic Disorder

Characteristics. Age at onset of DD ranged from 5.14 to 12.8 years (mean = 8.71 years, SD 1.80 years). As already noted, 32 of 55 cases had a superimposed MDD at study entry. Furthermore, 26 (47.3%) had anxiety disorder and 18 (32.7%) had externalizing disorder. TABLE 2

0- 12" 12-24 24-36 36-48 48-60 60-72 72-84 84-96 96-108

n at Start of Interval

55 55 49 33 24 15 11 7 3

Hazard Function (SE)

.oo

(.OO) .08 (.04) .34 (.09) .28 ( . l o ) .46 ( . 1 5 ) .31 ( . I S ) .22 (.16) .40 (.28) 1.33 (.70)

x2

x2

Probability of Recovery From Onset in First-Episode Dysthymic Disorder

Interval From Onset (mo)

Recovery. Forty-five children had recovered from the D D . Ten cases were censored: 3 were still in the episode and 7 discontinued study participation before recovery. Table 2 presents numerically the cumulative probability of recovery from DD by 12-month intervals and the hazard ratio (and standard error) for each interval. Recovery from dysthymia appeared unlikely during the initial 2 years of the disorder (the first year is required for the diagnosis). Median time to recovery was 3.91 years (SE = 0.37); the cumulative probability of recovery was .35 (SE = .066) by 3 years and .77 (SE = .06) by 6 years from onset. Although the probability of remission was low for each year of illness, if all these youths were to be followed for 8 years, 89% of them could be expected to have recovered from D D . Predictors of Recovery. From among the eight predictors, only comorbid externalizing disorder was retained in the final model (regression coefficient = -.968, SE = .442, = 5.96, df = 1, p = .0146). Median duration of dysthymia was estimated as 6.01 years (SE = 1.1 1) for children who had externalizing disorder and 3.70 years (SE = 0.36) for children who did not have externalizing disorder. Figure 2 depicts the Kaplan-Meier functions for these two groups of children. Treatment and Recovery. No child received pharmacological treatment for dysthymia, but 42 (76.4%) had psychosocial intervention. When added to the model with externalizing disorder, psychosocial treatment (yes versus no) had no evident impact on time to recovery from DD (regression coefficient = -.317, SE = .365, =0.72, df = 1, p = .3978).

Cumulative Probability of Recovery at Start of Interval

.oo .oo .07 .34 .5 1 .69 .77 .82 38 .98b

Duration required to meet DSM-III criteria. bAt end of last interval.

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Time From Onset (in months)

Fig. 2 Cumulative probability of recovery from onset in first-episode dysthymic disorder (DD) as a function of comorbid externalizing disorder.

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KOVACS ET A L .

DISCUSSION

To contribute to a comprehensive characterization of the course of childhood-onset MDD and DD, in this article we focused on first episodes and prognosticators of recovery that can be identified at initial referral or clinical contact. The findings suggest that although the likelihood of recovery from first-episode depression is excellent, the episodes are long. Furthermore, the initial stages of affective disorder appear to run their own course and show little variability as a function of many clinical and demographic characteristics. Recovery From First-Episode Major Depressive Disorder

There are now three studies (including the present one) that examined first-episode major depression in clinically referred or community-based youths and used multivariate procedures to model recovery from onset (Lewinsohn et al., 1994; McCauley et al., 1993). The results indicate that median duration of first-episode major depression may be up to four times longer in clinically referred youths than community-based adolescents. In young patients, median episode length is 8 to 9 months; 30% to 40% can be expected to recover by 6 months from onset, 70% to 80% by 12 months from onset, and 80% to 95% by 18 months from onset of the episode (present study; McCauley et al., 1993). First-episode major depression was similarly protracted in nonreferred high-risk offspring, with recovery rates between 74% (Warner et al., 1992) and 79% (Keller et al., 1988) by 1 year from onset. It remains to be seen whether subsequent episodes have similar durations. Among baseline clinical variables that have been examined, none has yet been shown to consistently predict recovery from major depression in juveniles. W e found that comorbid nonaffective psychiatric disorder that could be identified at initial referral had no appreciable impact on length of first-episode major depression. Similar results were reported when comorbidity was defined as occurring at any point during the depressive episode (Kovacs et al., 1984) or youngster’s lifetime (Lewinsohn et al., 1994) and in referred as well as nonreferred youths (Lewinsohn et al., 1994; McCauley et al., 1993); only one study had contrary findings (Keller et al., 1988). Although youths with major depression often have other concurrent disorders, clinicians treating first-episode cases therefore should

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be able to target the depression first and focus on other problems subsequently. Although the indications are that early in the course of MDD, its duration is not prolonged by concurrent nonaffective psychopathology, this may not be the case over time. As youngsters become older, different forms of nonaffective disorders develop. For example, substance abuse, increasingly likely with age, has been shown to have a negative effect on recovery from depression in community-based adults (McLeod et al., 1992). Consistent with data on adults (Keller et al., 1982), when major depression was superimposed on dysthymia, recovery from MDD was faster than in the absence of underlying dysthymia. This probably reflects that it is easier to return to a symptomatic (dysthymic) baseline than an asymptomatic state. The relationship of dysthymia and recovery from major depression in youths, however, needs closer scrutiny; Warner and associates (1992) found a clinically notable but statistically nonsignificant trend in this regard, whereas in a smaller group of our cases (Kovacs et al., 1984) and other studies (Lewinsohn et al., 1994; McCauley et al., 1993), no associations were detected. Age at onset has been found to affect duration of major depression in youngsters in some but not in other studies. This may suggest that a relationship does exist, although it probably is not very strong. Both in our and another first-episode clinical cohort (McCauley et al., 1993), age at onset had no appreciable impact on recovery. In a smaller sample of 42 cases that included some episodes other than the first, we found that children younger at onset of major depression had longer episodes (Kovacs et al., 1984). Among youths in the community (Lewinsohn et al., 1994) and nonreferred but at-risk offspring (Warner et al., 1992), earlier onset also was associated with more protracted major depression. Thus, earlier onset could signify somewhat greater illness severity or less individual resiliency. Recovery from major depression in youths does not seem to be appreciably influenced by sex and social class or by depression severity defined by symptom count or as endogenous, melancholic, or psychotic subtype (Lewinsohn et al., 1994; McCauley et al., 1993; Strober et al., 1993; Warner et al., 1992). However, some of these variables (e.g., sex) have been shown to influence onset or recurrence (e.g., Coryell

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F I RST- E P I S 0 D E D E 1’R E S S I 0 N

et al., 1992; Lewinsohn et al., 1994). Therefore, consistent with data on adults (Keller et al., 1992; Young et al., 1987), some features that are associated with a particular episode in youths may provide limited information about other episodes. Mental health service use has been consistently related to longer major depression in naturalistic studies of youths (present sample; Lewinsohn et al., 1994; McCauley et al., 1993) and prospectively followed clinical samples of adults (Coryell et al., 1994). Such results may reflect that treatment was more likely to be sought as the episode persisted (Coryell et al., 1994; Lewinsohn et al., 1994). However, when we used a statistical approach in which the timing of pharmacotherapy along the course of major depression was considered, the negative relationship still remained. To understand the interface of mental health service use and depressive episode length in naturalistic settings, a larger sample of treated cases must be studied in order to take into account confounds such as treatment intensity, episode severity, and patient compliance.

or represent a way of coping with the negative social reactions that conduct disturbances elicit. The possibility that nonaffective psychopathology may result in greater morbidity of minor depressive disorder also is suggested by a prospective study of high-risk adults (Coryell et al., 1992). Very little is known about the naturalistic treatment of DD in youths. Follow-up data on adults suggest no evident association between treatment intensity and recovery from chronic affective disorder (Coryell et al., 1990). None of our patients received pharmacotherapy for dysthymia, and we detected no difference in episode lengths as a function of having received psychotherapy. Because of the protracted duration of this form of depression as well as the likelihood of eventually poor social functioning (Klein et al., 1988b), treatment studies are urgently needed. Our findings suggest that treatment for dysthymic youths with comorbid externalizing disorder also should target the behavior problems and their consequences to facilitate faster recovery from the depression.

Recovery From First-Episode Dysthymic Disorder

General Implications

The diagnosis of DD in childhood requires 1 year of symptomatology (American Psychiatric Association, 1980, 1987). However, dysthymia in clinically referred youths is much more protracted, with a median firstepisode length of 3.9 years. Although this form of depression in juveniles has received scant attention in clinical studies (Asarnow and Ben-Meir, 1988; Ferro et al., 1994; Shain et al., 1991), none of which examined recovery, observations on nonreferred cases confirm its chronicity. In one sample of at-risk offspring, median duration of DD was 5 years (Keller et al., 1988); in another small group, a 3-year average duration was reported (Klein et al., 1988a). In community-based adolescents with first-episode DD, average duration was between 2.5 and 3.4 years (Lewinsohn et al., 1991). The protracted course of dysthymia in youths is consistent with retrospective reports of childhood-onset chronic depression by some depressed adults (Akiskal, 1994). From among baseline clinical features, only comorbid externalizing (conduct, oppositional, attention deficit) disorder was related to duration of dysthymia. DD lasted almost 2 % years longer in the presence of this comorbidity than otherwise. In some children, therefore, chronic depression may be exacerbated by and/

O ne of the noteworthy findings from this study is that the number of depressive episodes in referred juveniles appears to convey important information about the likelihood and correlates of recovery. However, the ultimate clinical and practical implications of our results are constrained by the sample’s characteristics, including an overrepresentation of lower socioeconomic classes. In addition, the type, intensity, and duration of treatments that our subjects received were not under our control, and the exact nature of psychosocia1 interventions could not be verified. Therefore, we cannot disentangle possible effects of particular therapies on recovery from depression in our sample. However, we can conclude that first-episode depression appeared to “run its own course.” In other words, in first occurrence of morbid depression, the predictive value of a variety of clinical and demographic variables was seemingly reduced or neutralized. Consistent with findings by Lewinsohn et al. (1994), subsequent depressive episodes would be expected to have different correlates because of the negative functional and social consequences as well as possibly enduring physiological changes that have been initiated (Kovacs and Goldston, 1991; Post, 1992; Puig-Antich et al., 1985). Because information on correlates and predictors of course and

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outcome is relevant to treatment efforts and mental health policy, characterization of childhood-onset depression across multiple episodes should be a research priority. Furthermore, the protracted duration of firstepisode depression clearly suggests the importance of aggressive treatment as early as possible, aiming at rapid symptom reduction and prevention of secondary functional impairment.

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