Apathy in Alzheimer's disease

Apathy may be associated with BRS dysfunction in AD, and treatment with methylphenidate, a dopamine agonist, may be beneficial in alleviating apathetic symptoms. Future research should include a larger sample size and more definitive measures on where the BRS dysfunction is occurring.This study assessed patients with Alzheimer's disease (AD) to evaluate whether apathetic patients (n=11) exhibit more brain reward system (BRS) dysfunction than non-apathetic patients (n=6), using the BRS probe, dextroamphetamine (10mg/p.o.). Subjective, behavioural and physiological effects were monitored at baseline and hourly, post-drug. Apathetics were subsequently enrolled into a controlled methylphenidate crossover (20mg/day).Between-group analyses showed apathetics had more dysphoria, tension/anxiety, and inattention at baseline (p<0.05). Post-dextroamphetamine, apathetics still experienced less euphoria, reward and attention (p<0.05). Seven of 11 apathetics completed the methylphenidate crossover (5/7 responders). Further, dextroamphetamine results successfully predicted methylphenidate treatment response for apathy (p=0.01) and methylphenidate was more effective in reducing apathy than placebo (p=0.04).