Abstract
Introduction: Behavioral activation therapy (BAT) is designed to help individuals' approach and access sources of positive reinforcement in their life, which can serve a natural antidepressant function and efforts to help depressed people reengage in their life through focused activation strategies. Methods: In this study, 60 individuals were selected and randomly assigned to intervention and control groups. The intervention group received behavioral activation treatment, including eight treatment sessions and 5 weeks later, a follow-up study was conducted. The data were collected, using a Beck Depression Inventory-II and behavioral activation system (BIS)/ behavioral inhibition system (BAS) Carver and White questionnaires, before the intervention and after the intervention and five weeks after the intervention. SPSS 23 and analysis of covariance (ANCOVA) was used for data analysis. Results: Results showed a significant increase in the two components of the BAS including reward seeking and response to reward in the intervention group, which indicates an increase in positive affect and appetitive motivation for reward seeking and decreases the risk of depression. Also, the results showed a significant decrease in the BIS and depression in the intervention group, which indicates a decline in experiencing negative emotions. Conclusion: The implementation of BAT will cause depressed people to try to maximize future rewards and it's effective in improving the reward seeking and reward response in depressed people because this treatment will increase the positive reinforcement and lead to learning cues that predict possible rewards in environments.