Background: About one third of cancer patients suffer from a psychiatric disorder. However, only few studies feature long-term assessment of psychiatric disease in cancer patients, covering a broad range of diagnoses, and employing high-quality instruments.

Patients and methods: A total of 62 patients underwent assessments during a 3-year follow-up period after initial cancer diagnosis. The Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders was administered to measure psychiatric morbidity at baseline (t₁) and two follow-ups (t₂ and t₃). Follow-up assessments took place from 6 to 18 months (t₂) and from 24 to 36 months (t₃) after baseline. Biomedical and psychosocial factors were evaluated to identify predictors of psychiatric disorders using univariate and multivariate analyses.

Results: At t₁, at least one DSM-IV diagnosis was found in 29% of the cases. At follow-ups, the frequency of psychiatric morbidity increased to 36% at t₂ and 44% at t₃, respectively. New occurrence of psychiatric disease at follow-ups was 18% at t₂, and 38%, at t₃. Predictors of psychiatric disorders were low social support, low physical functioning, metastases, complications of disease, and loss of sportive activity.

Conclusion: Persistence and amount of newly diagnosed psychiatric disorders during three years after cancer treatment should be considered in the treatment of cancer patients, especially in individuals with accordant predictive factors.