Testosterone improves spatial memory in men with Alzheimer disease and mild cognitive impairment

Objective: To determine the efficacy of testosterone (T) supplementation on cognition in a sample of men with Alzheimer disease (AD) or mild cognitive impairment (MCI). Methods: Fifteen patients with AD and 17 patients with MCI aged 63 to 85 years completed a randomized, double-blind, placebo-controlled study. Nineteen participants received weekly intramuscular (IM) injections of 100 mg T enanthate and 13 participants received weekly injections of placebo (saline) for 6 weeks. Cognitive evaluations using a battery of neuropsychological tests were conducted at baseline, week 3, and week 6 of treatment and again after 6 weeks of washout. Results: Peak serum total T levels were raised from baseline an average of 295% in the active treatment group. Improvements in spatial memory (p < 0.05) and constructional abilities (p < 0.05) and verbal memory were evident in the T group. No changes were noted for selective and divided attention or language. Prostate specific antigen did not significantly change during this brief treatment. Conclusion: Testosterone supplementation may benefit selective cognitive functions in men with Alzheimer disease and mild cognitive impairment.