Depression profile in cancer patients and patients without a chronic somatic disease.

Background: To investigate whether depressed oncology patients show a specific depressive symptom profile, we compared depression symptoms in depressed cancer patients (CANCER-DEP) and depressed patients without a chronic somatic disease (NONCANCER-DEP).

Methods: Of a total of 2493 outpatients from a comprehensive cancer center and a center for psychosocial medicine, 1054 (42.3%) met the DSM-5 criteria for depression, measured with the Patient Health Questionnaire 9. Based on the Patient Health Questionnaire 9 scores, differences in severity of each of the 9 individual DSM-5 depression symptoms between CANCER-DEP (n = 542) and NONCANCER-DEP (n = 512) were examined. Non-depressed cancer patients (CANCER-NONDEP; n = 1216) served as a comparison group for somatic symptoms independent of depression in cancer. To control for depression severity, group comparisons were performed separately for patients with major depression and any depressive disorders.

Results: Depressed cancer patients reported significantly lower levels of the cognitive-emotional depression symptoms "worthlessness" and "suicidal thoughts" than NONCANCER-DEP. Only 1 out of 5 somatic depression symptoms ("changes in appetite") was more pronounced in CANCER-DEP than in NONCANCER-DEP. Confirming previous research, somatic depression symptoms occurred more frequently in CANCER-DEP than in CANCER-NONDEP.

Conclusions: The lower level of cognitive-emotional symptoms in CANCER-DEP than in NONCANCER-DEP is discussed in relation to different psychosocial phenomena. Our results indicate that somatic depression symptoms are similarly pronounced in CANCER-DEP and NONCANCER-DEP, and that CANCER-DEP show greater somatic depression symptoms than CANCER-NONDEP. The presence of high levels of somatic symptoms should alert clinicians to investigate for a potential comorbid depression in cancer patients.