Therapist-rated outcomes in a randomized clinical trial comparing cognitive behavioral therapy and psychodynamic therapy for major depression

•We model symptom change during depression therapy with therapist-rated outcomes.•Measures for severity on a given moment resulted in a linear symptom decrease.•Measures for improvement from treatment start resulted in a S-shaped symptom curve.•Differences in therapist characteristics influenced treatment efficacy findings.•We found no significant efficacy differences between CBT and psychodynamic therapy.

BackgroundThe efficacy of psychodynamic therapy (PDT) for depression is debated due to a paucity of high-quality studies. We compared short psychodynamic supportive psychotherapy (SPSP) to cognitive behavioral therapy (CBT) in a randomized clinical trial. We used therapist-rated outcomes to examine how the course of change during treatment could be best represented and to compare treatment efficacy, hypothesizing non-significant differences.MethodsThree hundred and forty-one adults meeting DSM-IV criteria for a depressive episode and with Hamilton Depression Rating Scale (HAM-D) scores ≥14 were randomized to 16 sessions of individual manualized CBT or SPSP. Severely depressed patients (HAM-D>24) received additional antidepressant medication. After each session, therapists rated the Clinical Global Impression Scale subscales 'Severity of Illness' (CGI-S) and 'Global Improvement' (CGI-I), and the DSM-IV Axis V Global Assessment of Functioning Scale (GAF). We fitted growth curves using mixed model analyses with intention-to-treat samples.ResultsCGI-S and GAF scores during treatment were best represented by a linear symptom decrease. CGI-I scores were best represented by an S-shaped curve with relative more improvement in the first and last phases than in the middle phase of treatment. No significant post-treatment treatment differences were found. A non-significant trend for a treatment effect on CGI-S scores vanished when controlling for therapist gender and profession.LimitationsTherapists were not specifically trained for CGI and GAF assessments.ConclusionsThese findings add to the evidence-base of PDT for depression. Therapist characteristics and differences between severity and improvement measures might influence ratings and need to be taken into account when using therapist-rated outcome measures.