Can Declining Rates of Dementia Be Explained by the Increased and Widespread Use of Psychotropic Medications?

Dementia, once described as the "silent epidemic," is now well known and greatly feared. Although the total number of dementia cases will increase worldwide because of increased life expectancy, eight population-based studies of dementia incidence or prevalence have suggested a declining age-specific risk in the United States and Europe during the past three decades. Many different psychotropic drugs have been introduced since the mid-1950s, and their clinical use has broadened and increased dramatically over time. Antidepressant drugs, second-generation antipsychotic drugs, lithium, valproate, carbamazepine, lamotrigine, electroconvulsive therapy, and exercise have all been found to activate or regulate various intracellular neurotrophic and neuroprotective processes. They promote neurogenesis and are protective in models of neurodegenerative diseases and ischemia. Because of their neurotrophic and neuroprotective effects, the widespread use of psychotropic drugs provides a plausible explanation for declining rates of dementia that have been observed.