Objectives. To update knowledge about the genetic background of behavioral and psychological symptoms of dementia (BPSD) in Alzheimer's disease (AD).
Review. BPSD emerge in the course of the disease progression in almost all AD patients. Both biological and environmental factors play a significant role in BPSD etiology. As regards the former, accruing data suggest a putative influence of genetic background on the clinical picture of dementing disorders and their treatment efficacy.
Conclusions. Multiple genes coding for proteins involved in the process of neurotransmission and potentially in AD neurobiology have been evaluated so far. In this paper we present and discuss results of studies that show significance of genetic variance in a number of genes, namely apolipoprotein E, serotonin and dopamine receptors, serotonin transporter, and catechol-O-methyltranferase, as a risk for behavioral disturbances in AD. The influence of genetic factors in BPSD etiology seems beyond controversy. However, a precise estimation of the importance of a single polymorphism is hardly possible due to prominent discrepancies in research findings. Potential sources of this variation, comprehensively reviewed and discussed, include differences in study methodology, selection and definition of target symptoms, selection errors, inadequate statistical power, and inherent limitations of genetic studies on complex traits.