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How effective are treatments for child and adolescent depression: a meta-analytic review |
Michael K D, Crowley S L |
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Authors' objectives To evaluate the effectiveness of psychosocial and pharmacological treatments for depression in children and adolescents.
Searching PsycLIT, ERIC and MEDLINE were searched; the search terms were not stated. In addition, the reference lists from identified articles were checked and several authors were contacted for details of 'in press' or unpublished studies. Handsearches were conducted of peer-reviewed journals, for example: the Journal of Consulting and Clinical Psychology, the Journal of the American Academy of Child and Adolescent Psychiatry, Behavior Therapy, Archives of General Psychiatry, School Psychology Review, Behavioral Psychotherapy, the Journal of Abnormal Child Psychology, the Journal of Clinical Child Psychology and the Journal of Affective Disorders. ProQuest Digital Dissertation Abstracts was searched back to 1980 for unpublished theses and dissertations.
Study selection Study designs of evaluations included in the reviewStudies of a within- or between-subjects group design were eligible for inclusion. The included psychosocial studies were either controlled studies or pre-test post-test studies. For a between-group study to be considered a controlled trial, random assignment to one of the various conditions was a requirement. All of the included pharmacological studies were controlled studies.
Specific interventions included in the reviewStudies of psychosocial or pharmacological treatments were eligible for inclusion. The most frequently used psychosocial treatment in the included studies was cognitive-behavioural group therapy, followed by nondirective supportive individual therapy, social skills group therapy, cognitive-behavioural individual therapy and relaxation group therapy. The included studies also used nondirective supportive group therapy, residential behavioural group therapy, aerobic exercise, individual relaxation therapy, role playing, family therapy, interpersonal therapy and various combinations of these interventions. Psychosocial treatments included preventive interventions. The controlled psychosocial studies mostly used waiting-list, placebo or no treatment as the control and most of these interventions were school-based. Other psychosocial studies were based in out-patient departments.
The number of psychosocial therapy sessions in the controlled trials ranged from 8 to 27 (median 10.5) and the duration of each treatment ranged from 2 to 12 weeks (median 8). The number of sessions in the pre-test post-test studies ranged from 5 to 36 (median 11) and the duration ranged from 4 to 24 weeks (median 12). The included pharmacological studies used imipramine, amitriptyline, desipramine, nortriptyline, fluoxetine and venlafaxine. The duration of treatment ranged from 4 to 8 weeks (median 6).
Participants included in the reviewStudies of children and adolescents aged 5 to 18 years who were 'at-risk', or either had symptoms or a diagnosis of depression, were eligible for inclusion.
Psychosocial studies included 'at risk' participants, those with depressive symptoms and those with a diagnosis of depression (including major depressive disorder and/or dysthymic disorder). The participants in the psychosocial studies included nonreferred and referred youngsters. The pharmacological studies included participants with a diagnosis of major depressive disorder, based on the American Psychiatric Association's DSM criteria and information obtained from self-report measures, interviews and observations.
Outcomes assessed in the reviewStudies that reported at least one outcome measure of depression, which was assessed after the intervention was completed, were eligible for inclusion. The duration of follow-up (where conducted) in the included psychosocial studies ranged from 1 month to 2 years post-treatment (median 7 weeks) among controlled studies, and from 1 month to 1 year post-treatment (median 4 months) for pre-test post-test studies. None of the included pharmacological studies had any follow-up assessments. The outcomes were assessed using measures of depressive symptoms and depressive diagnoses (based on self-report measures and interviews), one or more self-report measures, and combinations of self-report and interview.
How were decisions on the relevance of primary studies made?The authors did not state how the papers were selected for the review, or how many reviewers performed the selection.
Assessment of study quality Study validity was assessed using the following criteria: maturation, history, testing, instrumentation, regression, selection bias and experimental mortality. Each item was scored on a 3-point scale from 0 ( 'not a plausible threat to internal validity') to 3 ('by itself could explain findings'). An overall score was allocated to each study using these criteria and the following criteria: sample size, selection procedures, methodological rigour and measurement technology. The scores were then used to allocate the studies to one of the categories on a 5-point Likert scale: 5 (excellent), 4 (good), 3 (fair), 2 (inferior) or 1 (unacceptable). The authors did not state how the papers were assessed for validity, or how many reviewers performed the validity assessment.
Data extraction Two reviewers independently extracted and coded the data and resolved any differences through discussion. Inter-rater agreement was measured. An effect size (ES) was calculated for each study using the data provided (methods for dealing with different types of data were reported). Where studies used more than one assessment measure, the measures were 'collapsed' to provide one ES for each study. An ES of zero was used when data presented in the study could not be converted to an ES and the authors reported no significant difference between the active treatment and the placebo.
Methods of synthesis How were the studies combined?The studies were grouped according to whether psychosocial or pharmacological, and then by study design (controlled or pre-test post-test). A standardised mean difference ES was calculated. The characteristics of the individual studies were summarised in the text and the results were tabulated. The overall ES was then calculated along with 95% confidence intervals (CIs). For studies of between-subjects group design, unweighted ESs were calculated based on the variance estimated for untreated participants. For studies of within-subjects group design, unweighted ESs were calculated, summarising intrasubject variance. Pre-test post-test ESs were also calculated for studies of between-group design to facilitate useful comparisons across the two designs.
How were differences between studies investigated?The influence of the type and severity of depression, the participants' age (child or adolescent) and gender, and study quality on the results for psychosocial treatments was explored in additional sensitivity analyses. Child studies were defined as studies in which the participants' mean age was 12 years or younger; adolescent studies were defined as those in which the mean age was 13 years or older. Studies with at least 60% female participants were classified as majority female studies.
Results of the review Thirty-eight studies were included: 15 controlled psychosocial studies (1,108 participants), 9 pre-test post-test psychosocial studies (391 participants) and 14 controlled pharmacological studies (441 participants).
Inter-rater agreement for the extracted data ranged from 88 to 100% (mean 95.3%) and kappa ranged from 0.76 to 1.00 (mean 0.91).
Psychosocial studies.
Psychosocial treatment for depression led to moderate to large improvements in children; the overall mean difference ES at post- treatment (15 controlled studies, 23 treatments) was 0.72 (95% CI: 0.48, 0.94; range: 0.03 to 1.84). The improvement was maintained at a median follow-up of 6.5 weeks; the mean ES (8 controlled studies) was 0.64 (95% CI: 0.32, 0.95; range: 0.08 to 1.55). Similar results were obtained from pre-test post-test studies: the overall mean ES was 1.14 (95% CI: 0.75, 1.52; range: 0.23 to 2.30) at post-treatment, while the mean ES at a median of 36 weeks' follow-up (5 studies) was 1.26 (95% CI: 0.99, 1.52; range: 0.95 to 1.94).
Severity of depression.
Preventative psychosocial treatment regimens were not associated with any improvement; the mean ES (3 treatments) was 0.17 (95% CI: -0.17, 0.52). Psychosocial treatment for depression led to improvements in depression regardless of the severity of depression; the overall ES was 0.84 (95% CI: 0.29, 1.38, 1.11) for a diagnosis of major depressive disorder (5 controlled studies) and 0.81 (95% CI: 0.49, 1.11) for high symptoms of depression (15 treatments in controlled studies). From pre-test post-test studies, the overall ES was 1.32 (95% CI: 0.91, 1.73) for major depressive disorder and 0.72 (95% CI: -0.21, 1.66) for depressive symptoms.
Pharmacological studies (14 controlled studies).
Pharmacological treatments were not associated with any improvement in depression; the overall mean ES at post-treatment was 0.19 (95% CI: -0.08, 0.45; range: -0.88 to 1.19). Follow-up data were not reported.
Age.
The results suggested that psychosocial and pharmacological treatments were more effective for adolescents than children. The mean ES was 0.65 (95% CI: 0.34, 0.95) for controlled psychosocial child studies (9 studies) versus 0.93 (95% CI: 0.36, 1.49) for controlled adolescent studies (5 studies). Similar results were obtained for pre-test post-test studies (the data were presented). The mean ES for pharmacological child studies was 0.15 (95% CI: -0.12, 0.42) compared with 0.28 (95% CI: -0.24, 0.79) for adolescent studies.
Gender.
The results suggested that psychosocial treatments were more effective when the proportion of females was 60% or more. The overall ES was 0.90 (95% CI: 0.42, 1.38) when at least 60% of the participants were female (9 controlled studies) and 0.63 (95% CI: 0.32, 0.92) when less than 60% were female (6 controlled studies). Similar results were obtained for pre-test post-test studies (the data were presented).
Study quality.
The average ESs for the studies based on the assessment of quality were as follows: unacceptable (0.47), inferior (0.85), fair (0.73), good (1.33) and excellent (1.64). The ES increased with the quality of the study (correlation coefficient 0.67, P<0.001).
Authors' conclusions A variety of different psychosocial treatments produced clinically meaningful improvements in depression in children and adolescents, but most pharmacological treatments were not effective.
CRD commentary The review question was clear in terms of the study design, intervention, participants and outcomes. Several relevant sources were searched and attempts were made to locate unpublished studies and abstracts reported at conferences. It was unclear whether any language restrictions were applied, the search terms were not stated, and there were no details of the methods used to select studies for inclusion in the review. It was also unclear whether the method used to extract the data (two independent reviewers) was also used to assess validity. Validity was assessed using defined criteria but some aspects of study design, such as whether or not the controlled studies were randomised, were not reported clearly.
No information on the individual studies was presented, although the characteristics of the individual studies were summarised and described in the text of the review. The studies were appropriately grouped according to treatment (psychosocial or pharmacological) and then by study design. The studies were then combined in meta-analyses, although it was not clear whether this was appropriate since statistical heterogeneity was not assessed. All psychosocial treatments were combined and, again, this may not have been appropriate. For psychosocial studies, sensitivity analyses were used to explore the influence on the results of the type and severity of depression, the age of the participants and study validity, but not the type of intervention.
In view of the concerns highlighted, it is not clear whether the positive effect of psychosocial treatments applies to all types of psychosocial interventions. Hence, the conclusion should be interpreted with caution.
Implications of the review for practice and research Practice: The authors stated that there are a number of effective treatments for young people that should be implemented as soon as is practicable.
Research: The authors stated that large controlled clinical trials are required to assess the efficacy of psychotherapy and pharmacological treatments for children and adolescents with depression. They further stated that future research should explicitly report findings based on age and gender; that pharmacological trials should assess outcomes using consistent criteria; and that attention should be given to the methodology of future studies.
Bibliographic details Michael K D, Crowley S L. How effective are treatments for child and adolescent depression: a meta-analytic review. Clinical Psychology Review 2002; 22(2): 247-269 Indexing Status Subject indexing assigned by NLM MeSH Adolescent; Antidepressive Agents /therapeutic use; Child; Clinical Trials as Topic; Combined Modality Therapy; Depressive Disorder /diagnosis /psychology /therapy; Humans; Psychotherapy; Serotonin Uptake Inhibitors /therapeutic use; Treatment Outcome AccessionNumber 12002006104 Date bibliographic record published 31/08/2004 Date abstract record published 31/08/2004 Record Status This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn. |
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