Pretreatment depression severity in breast cancer patients and its relation to treatment response to behavior therapy

Major depressive disorder is prevalent in breast cancer patients. There is a paucity of research on variables associated with depression severity and the link between depression severity and response to psychotherapy. To provide optimal mental health services to breast cancer patients, examining correlates of depression severity and its relation to treatment response is critical.

In the context of a randomized trial of behavior activation and problem-solving therapy for depressed breast cancer patients, this study evaluated demographic (marital status, age, education), psychosocial (social support, environmental reward, anxiety, number of coexistent anxiety disorders), and cancer-related (bodily pain, length of diagnosis, cancer stage) variables associated with pretreatment depression severity. Second, the relation of pretreatment depression severity with posttreatment and 12-month response and remission was assessed.

For pretreatment depression severity, the overall regression model accounted for 40% of the variance, F(5, 74) = 9.87, p < .001. Less environmental reward and greater somatic anxiety were significantly and uniquely associated with depression severity. Depression severity was unrelated to treatment remission but was a significant moderator of treatment response at posttreatment and 12-month follow-up; individuals with higher depression severity were more responsive to therapy. For patients treated with behavior activation, environmental reward significantly mediated the relationship between pre- and posttreatment depression.

Consistent with behavioral models of depression, less environmental reward and greater anxiety might influence depression severity in breast cancer patients. Data support the efficacy of behavior therapy for breast cancer patients, particularly those with more severe depression.