Increasing Positive Outlook Partially Mediates the Effect of Empirically Supported Treatments on Depression Symptoms Among Adolescents

Applying experimental therapeutics to examine cognitive and chronological vulnerabilities as mediators of acute outcomes in cognitive-behavioral therapy and light therapy for winter depression

OBJECTIVE

We applied the experimental therapeutics approach to test whether acute treatment outcomes for winter seasonal affective disorder (SAD) are mediated by a cognitive mechanism in cognitive-behavioral therapy (CBT-SAD) versus a chronobiologic mechanism in light therapy (LT).

METHOD

Currently depressed adults with major depression, recurrent with seasonal pattern (N = 177; 83.6% female, 92.1% non-Hispanic White, M age = 45.6) were randomized to 6 weeks of LT or group CBT-SAD. SAD symptoms were assessed weekly on the Structured Clinical Interview for the Hamilton Rating Scale for Depression-SAD Version. At pre-, mid-, and posttreatment, participants completed measures of general depressogenic cognitions (Dysfunctional Attitudes Scale; DAS); SAD-specific negative cognitions (Seasonal Beliefs Questionnaire; SBQ); chronotype (Morningness-Eveningness Questionnaire; MEQ); and depressive symptoms (Beck Depression Inventory-Second Edition).

RESULTS

Parallel-process growth models showed evidence for hypothesized mechanisms. For SAD-specific negative cognitions (SBQ), both symptom measures showed (1) an effect of treatment group on the slope of the mediator, with CBT-SAD demonstrating greater decreases, and (2) an effect of the slope of the mediator on the slope of the outcome. These effects held for the SBQ but not the broader measure of depressogenic cognitions (DAS). For the chronotype measure (MEQ), treatment assignment affected change, whereby LT was associated with reduced "eveningness," but this was unrelated to change in symptoms.

CONCLUSIONS

CBT-SAD promoted decreases in SAD-specific negative cognitions, and these changes were related to decreases in symptoms. Consistent with the theory that LT corrects misaligned circadian rhythms, LT reduced eveningness, but this did not correspond to symptom improvement. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Changes in cognitive distortions and affectivity levels in adolescent depression after acute phase fluoxetine treatment

INTRODUCTION

It is supposed that both antidepressants and psychotherapies work in a manner consistent with cognitive theories of depression when changing negative affective and cognitive distortions. This study evaluated changes in cognitive distortions (i.e. systematic misinterpretations of new information) and affectivity in adolescent major depressive disorder (MDD) after acute phase treatment with fluoxetine.

METHODS

Twenty-five adolescents (mean age 15.10 years (SD = 1.19); 17 (68%) females) with MDD receiving fluoxetine were followed for 8 weeks. Clinician rating scales of MDD and self-reports of cognitive distortions and affectivity were completed before and after the treatment.

RESULTS

Seven (28%) adolescents showed significant improvement in cognitive distortions, 11 (44%) showed a significant decrease in negative affect, and 15 (60%) showed a significant increase in positive affect. The responders to fluoxetine had significantly decreased level of negative affect (62.5%) and an increased level in positive affect (81.2%) compared to non-responders, whereas there were no differences between the two regarding changes in cognitive distortions.

CONCLUSIONS

Treatment with fluoxetine over 8 weeks led to reductions in cognitive distortions, with decreased negative and increased positive affect in adolescents with MDD. Improvements in affectivity levels closely corresponded to reductions in depressive symptoms and were greater than improvements in cognitive distortions.

Mechanisms of change in psychotherapy for depression: An empirical update and evaluation of research aimed at identifying psychological mediators

We present a systematic empirical update and critical evaluation of the current status of research aimed at identifying a variety of psychological mediators in various forms of psychotherapy for depression. We summarize study characteristics and results of 35 relevant studies, and discuss the extent to which these studies meet several important requirements for mechanism research. Our review indicates that in spite of increased attention for the topic, advances in theoretical consensus about necessities for mechanism research, and sophistication of study designs, research in this field is still heterogeneous and unsatisfactory in methodological respect. Probably the biggest challenge in the field is demonstrating the causal relation between change in the mediator and change in depressive symptoms. The field would benefit from a further refinement of research methods to identify processes of therapeutic change. Recommendations for future research are discussed. However, even in the most optimal research designs, explaining psychotherapeutic change remains a challenge. Psychotherapy is a multi-dimensional phenomenon that might work through interplay of multiple mechanisms at several levels. As a result, it might be too complex to be explained in relatively simple causal models of psychological change.

Mediators in the randomized trial of Child- and Family-Focused Cognitive-Behavioral Therapy for pediatric bipolar disorder

Mediation analyses can identify mechanisms of change in Cognitive-Behavioral Therapy (CBT). However, few studies have analyzed mediators of CBT for youth internalizing disorders; only one trial evaluated treatment mechanisms for youth with mixed mood diagnoses. This study evaluated mediators in the randomized trial of Child- and Family-Focused CBT (CFF-CBT) versus Treatment As Usual (TAU) for pediatric bipolar disorder (PBD), adjunctive to pharmacotherapy. Sixty-nine children ages 7-13 with PBD were randomly assigned to CFF-CBT or TAU. Primary outcomes (child mood, functioning) and candidate mediators (family functioning, parent/child coping) were assessed at baseline and 4-, 8-, 12- (post-treatment), and 39-weeks (follow-up). Compared with TAU, children receiving CFF-CBT exhibited greater improvement in mania, depression, and global functioning. Several parent and family factors significantly improved in response to CFF-CBT versus TAU, and were associated with the CFF-CBT treatment effect. Specifically, parenting skills and coping, family flexibility, and family positive reframing showed promise as mediators of child mood symptoms and global functioning. Main or mediating effects for youth coping were not significant. CFF-CBT may impact children's mood and functioning by improving parenting skills and coping, family flexibility, and family positive reframing. Findings highlight the importance of parent coping and family functioning in the treatment of PBD.

Mediators and Moderators of a School-Based Cognitive-Behavioral Depression Prevention Program

This study tested potential moderators and mediators of an indicated depression prevention program for middle school students, Positive Thoughts and Actions (PTA). Participants were 120 students randomly assigned to PTA, or a brief, individually administered supportive intervention (Individual Support Program, or ISP). Youths completed measures of depressive symptoms at baseline, post-intervention, and 12-month follow-up. Hierarchical regression was used to test three moderators-ethnic minority status, gender, and baseline depressive symptoms-and three mediators representing functional outcomes targeted by PTA-parent-child communication, attitude towards school, and health behavior. Ethnic minority status did not moderate PTA effects at post-intervention but did moderate PTA effects at 12-month follow-up. At 12 months, PTA appeared to be more effective for White participants than ethnic minority youth. Follow-up analyses suggested this moderation effect was due to the tendency of ethnic minority youth, especially those with fewer symptoms at baseline, to drop out by 12 months. Neither gender nor baseline depressive symptoms moderated the effects of PTA. Although PTA improved health behavior and attitudes toward school, there was no evidence that any of these functional outcomes measured mediated the impact of PTA on depressive symptoms. Future directions are discussed.