Brain tumors may present with multiple psychiatric symptoms such as mania, depression, psychotic symptoms. A 58-year-old woman with type 2 diabetes mellitus, hypertension, and hyperlipidemia admitted for diabetes control. She had depressive symptoms. Her neurologic examination and laboratory tests were normal. She was diagnosed as having depression and was given antidepressants. After 5 weeks, she was found unconscious in her house and was admitted to Emergency Department. Neuroimaging revealed a brain tumor in the left frontoparietal lobe. It is important for clinicians to be aware of that in rare cases, brain tumors can be neurologically silent and only present with psychiatric symptoms.