Fifty patients satisfying DSM-III-R criteria for mania were included i
n a naturalistic study. Manic patients were categorized into three dia
gnostic groups according to the DSM-III-R criteria of non-psychotic or
psychotic mania, and into the four groups obtained by the cluster ana
lysis of Double (Double, D.B. (1991) Compr. Psychiatry 32, 187-194). P
ersonal history and short-term outcome did not differ between the DSM-
III-R diagnostic groups nor between the groups defined by cluster anal
ysis, although non-psychotic manic patients more frequently tended to
receive lithium and/or anticonvulsant drugs alone at discharge. Cluste
r 3 patients presenting with manic and 'schizophrenic' symptoms had an
earlier age of onset and were younger at admission than patients in t
he other three clusters.