Co-occurrence of neuropsychiatric syndromes in demented and psychotic institutionalized elderly.

Objectives: To explore and determine the clinical figures of behavioral syndromes from the factor structure of the Neuropsychiatric Inventory-Nursing Home version (NPI-NH) in demented and psychotic patients.

Setting: Two nursing homes and two long-term care homes.

Design: Observational, cross-sectional.

Participants: One hundred and sixty-three institutionalized elderly with dementia or psychosis (66.9% female), mean age 80.9 +/- 9.1 years.

Measurements: The NPI-NH includes 12 neuropsychiatric symptoms and a distress scale. The product score of frequency (F) and severity (S) ratings provides an overall score for each of the 12 items. An exploratory principal component analysis with Varimax rotation was performed on the F x S scores according to patients' diagnosis.

Results: High internal consistency of the NPI-NH was found (alpha = 0.8). In demented patients a 4-factor solution was found that explained 63.9% of the variance, with the syndromes: (a) 'hyperactivity'; (b) 'affective'; (c) 'psychosis'; and (d) 'Hallucinations'. A four-factor solution was also found in psychotic patients, explaining 61.3% of variance, with syndromes: (a) 'affective'; (b) 'frontal lobe symptoms'; (c) 'sundowning'; and (d) 'psychomotor agitation'. A syndrome was unlikely to appear alone but was most likely to occur with other syndromes. A specific pattern of syndrome co-occurrence were found in demented (a + b + c in 30.5% of cases) and psychotic patients (a + b + c + d in 35.2% of cases).

Conclusion: The syndrome taxonomies are consistent with the diagnostic criteria. The clinical use of syndrome co-occurrence could help to further understand and evaluate behavioral changes in pharmacological and non-pharmacological treatments.