Depression is common in cancer patients. However, only limited evidence is available in Asian populations. The authors proposed to examine the prevalence of depression in Thai patients with cancer. In addition, factors associated with depression were also determined.

This cross-sectional study conducted in cancer patients admitted in a university hospital during December 2006 - December 2007. Patient Health Questionnaire (PHQ-9) was used to assess all cancer patients. Suicidal risk was assessed by using the Mini-International Neuropsychiatric Interview (M.I.N.I.) in the module of suicidal risk assessment.

Of 108 cancer patients, 29.6 % was diagnosed with depressive disorder (mild: 14.8 %, moderate: 5.6 %, severe: 9.3 %). However, only 25.0 % of all depressed patients were recognized as depressive disorder by primary physician. According to M.I.N.I., 28.1 % of these depressed cancer patients had moderate to severe level of suicidal risk. In addition, the findings suggest that increased risk of depression is significantly associated with increased pain score, less number of cancer treatments (< 2 methods), increased educational duration (>13 years), increased age (> 50 years old) and female group.

Prevalence of depression is high in cancer patients. However, depressive disorder in those patients is frequently misdiagnosed. They are also associated with several factors including pain, a number of cancer treatments, education duration, age and sex. To improve quality of life, increase compliance of treatments and prevent of suicide, screening for depressive disorder in those patients should be strongly recommended.