title: A study of affective psychosis in twins.
mesh_terms: D000328:Adult; D000341:Affective Disorders, Psychotic / Q000235:genetics*; D004200:Diseases in Twins; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011247:Pregnancy; D014430:Twins, Monozygotic