This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Psychiatry
Suicidal tendencies seen in -a) Depressionb) Posttraumatic stress disorderc) Schizophreniad) Substance abusee) Anxiety 
Select and explain. 
A. abc, B. ad, C. acd, D. bde
C: acd
Answer: C: acd 
Explanation: Causes/Risk factors for suicide
Psychiatric disorders : - Depression (most common), alcoholism (2nd mc), Drug/Substance dependence, Schizophrenia, Dementia.

Physical illness : - Cancer, AIDS, Multiple sclerosis, Head trauma.
Psychosocial factors : - Failure in love, marital difficulties, family dispute, illegitimate pregnancy.
Biological factors : - Decrease in serotonin
Other - Male sex, Age > 40 years, Single (Unmarried, divorced or widowed), previous suicide attempt, social isolation.