Prevalence of neuropsychiatric symptoms in young-onset compared to late-onset Alzheimer's disease - part 1: findings of the two-year longitudinal NeedYD-study.

BACKGROUND/AIMS: Knowledge about neuropsychiatric symptoms in young-onset Alzheimer's disease (YO-AD) is scarce, but essential to establish a prognosis and plan care for YO-AD patients. The aim of this study is to assess frequency parameters of neuropsychiatric symptoms in YO-AD over 2 years and investigate whether there are differences compared with late-onset Alzheimer's disease (LO-AD).

METHODS

98 YO-AD and 123 LO-AD patients and caregivers from two prospective cohort studies were included and assessed every 6 months for 2 years, using the Neuropsychiatric Inventory to evaluate neuropsychiatric symptoms.

RESULTS

Over the course of 2 years, the incidence, prevalence and persistence of neuropsychiatric symptoms were in general lower in YO-AD than in LO-AD, specifically for delusions, agitation, depression, anxiety, apathy, irritability and aberrant motor behavior. Frequency of individual symptoms showed large variability in both groups. Within the group of YO-AD patients, apathy was the most prevalent symptom.

CONCLUSION

Neuropsychiatric symptoms, notably apathy, should be paid appropriate attention to in the diagnosis and treatment of YO-AD patients. Further research is needed to gain insight into the mechanisms underlying the differences in neuropsychiatric symptoms between YO-AD and LO-AD.