Symptom-Specific Effects of Counselling for Depression compared to Cognitive Behavioural Therapy

Abstract

Introduction: Cognitive Behavioural Therapy (CBT) and Counselling for depression (CfD) are recommended first-line treatments for depression. They have different approaches to bring about symptomatic change, yet there is little understanding of the impact those approaches have on change during treatment. This study aimed to identify whether CBT and CfD target different symptoms and explore the implications of modelling choices when quantifying change during treatment. Methods: The study included a retrospective cohort of individuals with a diagnosis of depression, who had received five or more sessions of CBT or CfD, from primary/community care psychological therapy (IAPT) services in England. Symptom specific effects of treatment were identified using moderated network modelling including all items from the PHQ-9 and GAD-7. Change was modelled several ways within the whole sample and a propensity score matched sample (n=3446). Results: The whole sample (N=12,756) were predominantly female (68.5%), the mean age was 39.1 (13.3). CBT for depression directly affected excessive worry, trouble relaxing, and apprehensive expectation. CfD directly affected thoughts of being a failure. CBT had a stronger influence on changes between suicidal ideation and concentration, whereas CfD had a stronger influence on the associated change between being easily annoyed and apprehensive expectation. There were inconsistencies when modelling change using the first and second appointments as the baseline. Residual score models produced more conservative findings than models using difference scores.Conclusions: CfD and CBT for depression have differential effects on symptoms demonstrating specific mechanisms of change. CBT was uniquely associated with changes in symptoms associated with anxiety so may be better suited to those with anxiety symptoms comorbid to their depression. When assessing change the baseline should be the first therapy session not the pre-treatment assessment with residual scores preferred over difference score methods.