Hormones are widely considered to cause powerful psychological effects and because of this psychiatrists may be asked to advise general practitioners, consultants in other specialities or patients about the relationship between hormones (including sex hormones) and psychiatric disorder. Sex hormones may be relevant to psychiatry in three ways:(a) Sex hormones may play a role in the pathophysiology of psychiatric disorders.(b) These agents may be utilised for treatment of psychiatric disorder.(c) Administration of sex hormones may cause psychiatric side-effects.