The Natural History of Psychosis and Depression in Dementia With Lewy Bodies and Alzheimer’s Disease: Persistence and New Cases Over 1 Year of Follow-Up

Background: Few data are available regarding thenatural course of psychiatric symptoms in dementia with Lewybodies and Alzheimer’s disease. To acquire this information isessential to inform differential diagnosis and treatmentdecisions.

Method: The current study provides prospectivedata regarding a representative case-register cohort of patientswith operationalized clinical diagnoses of dementia with Lewybodies (N = 82) or Alzheimer’s disease (N = 132), with verifiedaccuracy of clinical diagnosis against postmortem examination.Psychosis (Columbia University Scale for Psychopathology inAlzheimer’s Disease) and depression (Cornell Scale for Depressionin Dementia) were assessed at baseline and annual follow-up.

Results: Visual hallucinations weresignificantly more likely to be persistent in patients sufferingfrom dementia with Lewy bodies (chi² = 19.1, df = 1, p< .0001). Although a number of other psychiatric symptoms werealso more frequent at baseline in dementia with Lewy bodypatients, they were not significantly more likely to persist.Delusions and auditory hallucinations did, however, persist inmore than 40% of patients across both diagnostic groups. Patientssuffering from dementia with Lewy bodies were significantly morelikely to develop new auditory hallucinations over the year offollow-up (chi² = 14.4, df = 1, p < .0001).

Conclusion: These results confirm that, althougha number of psychiatric symptoms are common in dementia with Lewybodies, it is only visual hallucinations that are significantlymore persistent, with important treatment implications.