The risk increase was highest at the initiation of antipsychotic use.
"As adverse effects, antipsychotics may cause sedation, orthostatic hypotension, and arrhythmias, which all may lead to falls. Among older persons, falls are the most common reason for traumatic brain injuries," Researcher Vesa Tapiainen from the University of Eastern Finland explains as a possible mechanism for the association.
Community-dwellers with Alzheimer's disease who used antipsychotics had a 29% higher risk of head injuries and a 22% higher risk of traumatic brain injuries when compared to community-dwellers with Alzheimer's disease who did not use antipsychotics. Among persons with Alzheimer's disease, antipsychotics are commonly used to treat neuropsychiatric symptoms of Alzheimer's disease.
According to clinical care guidelines, treating the cause of these symptoms, such as pain, is the first-line option, and secondly, non-pharmacological treatments should be prioritized. The use of antipsychotics should be restricted to the most severe symptoms (such as severe aggression, agitation, or psychosis). Following care guidelines and by carefully considering benefits and risks of adverse effects and events could possibly lower the incidence of head injuries and traumatic brain injuries.
The study was conducted using the nationwide register-based MEDALZ cohort, which includes Finnish community dwellers with a newly diagnosed Alzheimer's disease in 2005-2011 (70,719 persons). Persons were excluded if they had a prior head injury, antipsychotic use within one year prior to antipsychotic initiation or if they fulfilled other exclusion criteria of this study. The final study population was 21,795 persons who initiated antipsychotic use and 21,795 persons who did not use antipsychotics.
Medicine use was extracted from the Finnish Prescription Register. Chronic diseases, use of other medications, and socioeconomic position were taken into account.