This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Mood disorders, Subject name: Psychiatry
Most common mental disorder as a cause of suicide 
Select and explain. 
A. Mania, B. Depression, C. Alcohol dependence, D. Schizophrenia
B: Depression
Answer: B: Depression 
Explanation: Suicide is a model of psychiatric emergencies and is also the commonest cause of death among the psychiatric patient&;s psychiatric disorders are a major cause of suicide, for example, depression(1major depression 2depression secondary to a serious physical illness 3reactive depression), alcoholism and drug dependence and schizophrenia (Ref: a sho textbook of psychiatry, Niraj Ahuja, 7th edition, pg no.222)