Objective: To evaluate the prostate cancer effects of androgen deprivation therapy (ADT) by using a systematic set of methods to calculate specific cognitive functions in men with locally advanced or metastatic prostate cancer.

Materials and methods: From April 2014 to February 2016, a prospective, comparative study was done to evaluate the cognitive effects of hormone therapy. Group 1 consisted of 78 patients with locally advanced or metastatic prostate cancer who received complete ADT treatment continuously for 12 months and group 2 (control group) consisted of 78 patients who underwent radical prostatectomy without any additional treatment. The Montreal Cognitive Assessment (MoCA) test and the Frontal Assessment Battery (FAB) test with Turkish language version were used to evaluate multiple domains of cognitive function.

Results: Post-treatment results of both tests revealed that patients in group 1 achieved lower mean total scores than group 2. In MoCA test, the deficits were especially prominent in the areas of language ability and short-term memory capacity (P < .05 and P < .05). No significant differences could be identified between groups in respect to attention, executive functions, visuospatial abilities, abstract thinking, calculating abilities, and orientation. In FAB test, the deficits were especially prominent in the areas of mental flexibility and inhibitory control (P < .05 and P < .05). No significant differences could be identified between groups in conceptualization, motor series, conflicting instructions, and environmental autonomy.

Conclusion: ADT affects cognitive functions such as language ability, short-term memory capacity, mental flexibility, and inhibitory control. Urologists should keep in mind these side effects and inform the patients and their families for the early symptoms of cognitive dysfunction.