Mianserin is a tetracyclic compound advocated for the treatment of depressive illness and depression associated with anxiety. It combines antidepressant activity with a sedative effect and has an EEG and clinical activity profile similar to that of amitriptyline. It has an overall efficacy comparable with amitriptyline and imipramine in depressive illness, but at dosages which have achieved a similar overall clinical improvement, mianserin causes significantly fewer anticholinergic side effects than amitriptyline or imipramine and also appears less likely than these drugs to cause serious cardiotoxicity on overdosage. Mianserin also has anti-anxiety activity, but its role in treating patients with anxiety associated with primary depression has still to be clarified. Mianserin appears to be well tolerated by the elderly and by patients with cardiovascular disease, including those recovering from a recent myocardial infarction, and does not appear to antagonise the action of adrenergic neurone blocking antihypertensive drugs or affect the anticoagulant action of phenprocoumon.