BackgroundOne third of adults with cancer suffer from common mental disorders in addition to their malignant disease. However, it is unknown whether this proportion is the same in patients who have brain tumors and which factors modulate the risk for psychiatric comorbidity.MethodsIn a multicenter study, patients with high‐grade glioma at 13 neurooncology clinics were enrolled consecutively and interviewed with the Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders (SCID) to diagnose common mental disorders. Predictors of psychiatric comorbidity were investigated using binary logistic regression.ResultsSix hundred ninety‐one patients were interviewed. The proportion of patients who had mental disorders was 31% (95% confidence interval [CI], 28%–35%). There was evidence for an association of psychiatric comorbidity with the following factors: younger age (odds ratio [OR], 1.9; 95% CI, 1.1–3.4; p = .04), stable disease versus complete remission (OR, 1.7; 95% CI, 1.1–2.8; p = .04), lower income (OR, 1.7; 95% CI, 1.0–2.8; p = .04), living alone (OR, 1.6; 95% CI, 1.0–2.6; p = .05), fatigue (OR, 1.6; 95% CI, 1.1–2.4; p = .03), and impaired cognitive functioning (OR, 2.3; 95% CI, 1.5–3.6; p < .01). There was no evidence for independent effects of gender, histology, affected lobe, time since diagnosis, or employment status.ConclusionsApproximately one third of adult patients with high‐grade glioma may suffer from a clinically relevant common mental disorder, without notable disparity between the genders. In particular, clinicians should pay attention to possible comorbidities for cases in which patients exhibit compromised subjective cognitive function, are younger than 50 years, maintain a state of stable disease, or live alone.