[Depressive stupor--malignant neuroleptic syndrome--serotonin syndrome. A case contribution to a difficult differential diagnosis].

Depressive stupor and malignant neuroleptic syndrome are very well-known problems in clinical psychiatry. The serotonin syndrome, however, a potentially life-threatening side effect of treatment with serotonergic substances, has been included in the clinical differential diagnosis increasingly often in the last few years. The development of new serotonin selective antidepressants and selective reversible inhibitors of monoamine oxidase A has led to the use of more and more substances that can cause these life-threatening complications if they are taken in too high doses or together with other drugs. We present a 61 year old depressed female impatient who developed an abortive malignant neuroleptic syndrome while being treated for depressive stupor. We discuss a possible relation between serotonin syndrome and a highly dosed combination therapy with moclobemide. Owing to the importance of both syndromes, we consider drug monitoring absolutely necessary for patients who are being treated with new antidepressants, and especially for those who develop neurological and psychiatric complications when such preparations are given in combination with other drugs.