Agitation and neuropsychiatric symptoms in Alzheimer's disease: Potential for reverse causal associations.

Agitation is a common complex neuropsychiatric symptom in older adults. Agitation is well-interconnected with other neuropsychiatric symptoms (NPS). A recent study by Nagata and colleagues examined correlates between agitation and NPS in each dementia stage, ranging from mild to moderate and severe, using data from the Clinical Antipsychotic Trials of Intervention Effectiveness-Alzheimer's Disease. They found irritability consistently correlates with agitated behaviors in moderate and severe stages of Alzheimer's disease (AD), and sleep disorders influence the agitation in the severe stage of AD. Here, we discuss the strengths and limitations of the study and highlight potential reverse causality of NPS and AD.