Androgen deprivation, which can be accomplished via drug treatment using gonadotropin-releasing hormone (GnRH) agonists, antiandrogens, or both combined, is widely used in the treatment of prostate cancer. Androgen deprivation therapy (ADT) can delay cancer progression and be life-prolonging. As with almost all cancer treatments, ADT comes with side effects and one of the most concerning is the possibility of accelerated brain aging and cognitive decline. Patients and their friends and family may notice diminished memory, attention, and information processing. This is thought to be related to the neuroprotective supportive role that testosterone plays in the healthy brain. It enhances synaptic plasticity, improves mitochondrial function, and is anti-inflammatory. Reducing androgens to castration levels may mean loss of this protection.