Relation between the Frequency of Stressful Life Events and the Effectiveness of Cognitive Behavioral Therapy versus Short-term Psychodynamic Supportive Psychotherapy in the Outpatient Treatment of Depression

Abstract

The aim of this study was to investigate the relation between the frequency of stressful life events (SLEs) and the effectiveness of cognitive behavioral therapy (CBT) versus short-term psychodynamic supportive psychotherapy (SPSP) in the outpatient treatment of depression. A previous non-inferiority trial showed the non-inferiority of SPSP to CBT and research supported that SLEs are associated with a negative treatment outcome. However, the effect of the frequency of SLEs on the treatment outcome of CBT compared to SPSP was unknown. Additionally, because a SLE could increase the level of depression symptoms, this study investigated the correlation between the frequency of SLEs and the level of baseline depression. The data was based on a randomised clinical trial of 341 depressed patients, who were randomly assigned to either CBT or SPSP. The primary outcome measures were the Hamilton Depression Rating Scale (HDRS) administered at intake and at posttreatment assessment, and the List of Threatening Experiences (LTE) administered at intake. The data was analysed by performing a repeated measures Analysis of Covariance (RM-ANCOVA) and a correlation-analysis. A non-significant 3-way-interaction effect was found between the frequency of SLEs, treatment group and time of measurements (F (1,190) = 0.870, p = .352). This means for clinical practice that the frequency of SLEs is not of significant importance to choose one treatment above the other. A low positive correlation was found between the frequency of SLEs and baseline level of depression symptoms. Clinicians should consider that exposure to a SLE is a significant predictor for the level of depression symptoms. Keywords: Stressful life events, CBT, SPSP, randomised clinical trial, HDRS, LTE