Background: The prevalence of insight was examined longitudinally in p
sychotic patients with schizophrenia (n = 86), bipolar disorder (n = 5
2), major depressive disorder (n = 35) and other psychoses (n = 16). M
ethod: Before discharge and at 6-month follow-up, insight in first-adm
ission patients from 10 facilities in Suffolk County, New York was rat
ed as part of a modified Hamilton Depression Scale. Results: Initially
, 80% of depressives but approximately half with other diagnoses manif
ested insight. At follow-up, most patients demonstrated insight except
for the schizophrenic patients. After controlling for diagnosis, sign
ificant correlates of baseline insight were being married, hospitalize
d in a community or academic facility, intelligence and negative sympt
oms. At follow-up, after controlling for diagnosis and baseline insigh
t, prior treatment was predictive. This finding held for schizophrenic
patients separately. Conclusion: Lack of insight is more prevalent in
schizophrenia and improves over time. The components of prior treatme
nt leading to better insight should be explored.