Psychotic symptoms and age of onset in affective disorders. 
Prevalence of hallucinations and delusions was studied in 1,763 patients with unipolar major depression, bipolar affective disorder, and schizoaffective disorder.  The authors found that the presence of psychotic features was negatively associated with age of onset for the group as a whole, and bipolar affective disorder (manic or mixed type) specifically.  The clinical implications of the findings are discussed.