1. A case of acute delirious mania (Bell's mania) is described.2. It is regarded as an affective reaction with greater affinity to the fulminating agitated depressive state than to the manic phase of manic-depressive psychosis.3. The underlying physio-pathological mechanisms that lead to death in this malignant form of psychosis are discussed.4. The administration of electric convulsive therapy in the early stages of the illness is advocated.