AbstractBackgroundApathy is one of the most common and debilitating neuropsychiatric symptoms of Alzheimer’s Disease (AD). Two previous trials that suggested methylphenidate was safe and efficacious involved only 60 participants each, followed for 6 weeks. A larger, longer‐lasting trial was required to confirm those promising findings.MethodsADMET 2 was a phase III, placebo‐controlled, 6‐month, multi‐center, randomized (1:1, 20 mg methylphenidate per day or placebo) clinical trial that randomized 200 participants with AD and apathy. Primary outcomes included: (1) the mean difference on the Neuropsychiatric Inventory Apathy (NPI‐A) subscale scores measured as change from baseline to 6 months, and/or (2) the odds of a rating of improvement on the modified AD Cooperative Study Clinical Global Impression of Change (ADCS‐CGIC) at month 6 compared with baseline. Secondary outcomes included change in cognition, safety, and cost‐effectiveness measured monthly for up to 6 months.Results200 individuals were randomized (65.8% were males; 34.2% were females; avg age=76 years; 75.3% had some college education or greater; mean Mini‐Mental State Examination score at baseline was 18.9). There was a larger difference in the methylphenidate group compared with the placebo group in NPI‐A score from baseline to 6 months using a mixed model (Mean difference = ‐1.25; 95% CI: ‐2.03, ‐0.47, p = 0.002) with the largest change observed during the first two months. At 6 months, the ADCS‐CGIC showed that 43.8% (39/89) of participants in the methylphenidate group improved compared with 35.2% (32/91) of study participants in the placebo group (odds ratio 1.90 (95% CI: 0.95, 3.84), favoring methylphenidate, but not reaching statistical significance (p = 0.071)). There were no significant differences in other assessments. The safety profile was similar between the two groups.ConclusionADMET 2 showed a small to medium benefit for methylphenidate in the treatment of apathy in AD. The effect was observed at 2 months and was sustained throughout the 6 months of the study. Adverse events were mild. These results support previous observations in smaller studies. Methylphenidate offers a viable treatment for patients suffering from apathy in AD.