Background
Patients suffering from a major depressive disorder commonly indicate pessimistic views toward the future. Pessimistic thinking about the future is one of the cardinal symptoms of major depressive disorder and an important domain of the pathophysiology of depression. Few studies have evaluated changes in pessimistic thinking after undergoing cognitive behavioral therapy (CBT). A randomized clinical trial was performed with patients diagnosed with a major depressive disorder to specify whether receiving a course of cognitive behavioral therapy impacts pessimistic future thinking utilizing a future thinking task.
Methods
- Thirty-one patients with major depressive disorder were assigned randomly to either cognitive behavioural therapy (n=16) or a talking control (n=15) for a 16-week intervention.
- The main outcomes were the change in response time (RT) and the ratio of the responses for positive valence, measured by future thinking tasks.
- Secondary outcomes included the GRID-Hamilton Depression Rating Scale, the Beck Depression Inventory-Second Edition (BDI-II), the Dysfunctional Attitude Scale (DAS), and the world fluency test (WFT).
Results
- Considering the main outcomes, the cognitive behavioural therapy group indicated reduced response time for the positive valence (within-group Cohen’s d= 0.7, p=0.012 and negative valence (within-group Cohen’s d= 0.6, p= 0.03) in the distant future condition.
- The ratio of positive valence responses in both groups for all temporal conditions except for the distant past condition increased within the group.
- As for secondary effects, the cognitive behavioural therapy group indicated greater improvement than the talking control group regarding the need for social approval as measured by the dysfunctional attitude scale (p=0.012).
Conclusion
Major Depressive Disorder patients who received cognitive behavioral therapy indicated a reduced response time for the positive and negative valence in the distant future condition. Response time in the future thinking task for depressed patients may be a potential objective measure for the cognitive behavioral therapy treatment process. As the present randomized clinical trial is positioned as a pilot randomized clinical trial, a confirmatory trial with a larger number of patients is warranted to illuminate the cognitive behavioral therapy treatment process that impacts future thinking.