Depression and psychotic symptoms in dementia sufferers.

One hundred and twenty five patients with mild or moderate dementia according to the CAMDEX criteria, who were in contact with either a memory clinic or psychiatric services were assessed. Dementia was diagnosed according to the NINCDS ADRDA criteria, the Hachinski scale, DSMIIIR criteria, HAS AGECAT and the McKeith criteria for Senile Dementia of Lewy Body Type. Depression was diagnosed according to the DSMIIIR and RDC criteria and psychotic symptoms were assessed using the Bums Symptom Checklist. Cognitive impairment was evaluated using the CAMCOG schedule. Informants were interviewed at monthly intervals for one year concerning the symptoms of depression and psychotic symptoms experienced by the dementia sufferers. A repeat CAMCOG was undertaken one year after the initial assessment. The one month prevalence rates of delusions, visual hallucinations and delusional misidentification were 48.4%, 35.5% and 29.0% respectively. Each had a distinct pattern of associations, an impression supported by a principal components analysis which generated four psychotic factors, the three categories already discussed and comfort phenomena. Only sixteen patients had any insight into their psychotic symptoms and 61% were distressed by them. The annual incidence rate of psychotic symptoms was 46.7% and 53% of patients experienced symptom resolution. The number of months during which psychotic symptoms were experienced was significantly associated with the magnitude of cognitive deterioration. The one month prevalence rate of RDC major depression was 27.4%. An additional 27.4% of patients fulfilled the criteria for RDC minor depression. Having Alzheimer's disease was significantly inversely associated with both RDC major depression and DSMIIIR major depression. There were six patients with RDC depression in the context of vascular dementia, all of whom experienced depression for at least three months compared to only 33.3% of the patients with Alzheimer's disease. The annual incidence rate of RDC major depression was 10.6%