Incidence of the premenstrual syndrome in twins

CommentThis case fits the criteria for mania listed by the Diagnostic and Statistical Manual of Mental Disorders (3rd edition) and the ninth revision of the International Classification of Diseases.The association of mania and myxoedema must be very rare, and we can find no other reported case. 1-5The two usual psychiatric syndromes seen in myxoedema are, firstly, confusion and cognitive impairment resembling dementia, sometimes with clouding of consciousness; and, secondly, depressed mood with paranoid delusional ideas and often hallucinations.' 2 Irritability and violence are reported only in association with paranoid cases.2Our patient showed no psychiatric disorder until further metabolic disturbance was superimposed on his thyroid deficiency.After surgery he had a mental disturbance which may have been mild hypomania, which suggests that he may have been particularly susceptible to develop a mental disturbance from metabolic abnormality as an expression of his genetic predisposition indicated by the positive family history.We thank Professor J T Silverstone for his help and advice in preparing this report.