Effect of hormone therapy on personality traits: preliminary evidence in older men and women.

Hormone therapy in older women decreased conscientiousness and increased vulnerability.

• Sample included 22 community-dwelling cognitively normal women with a mean age of 75.2 years.
• Women received 0.625 mg/day conjugated equine estrogen with or without 2.5 mg/day medroxyprogesterone acetate for 3 months.
• HT decreased the conscientiousness domain (p < 0.01) and the conscientiousness facet of achievement striving (p < 0.01).
• HT increased vulnerability, a facet of neuroticism (p < 0.05).
• Personality was assessed using the Revised NEO Personality Inventory (NEO-PI-R) after active and placebo intervention phases in a randomized, double-blind, placebo-controlled cross-over design.

Testosterone therapy in older men decreased conscientiousness and increased vulnerability.

• Sample included 29 community-dwelling cognitively normal men with a mean age of 75.2 years.
• Men received 200 mg intramuscular testosterone enanthate every 2 weeks for 3 months.
• TT decreased the conscientiousness domain (p < 0.05) and the conscientiousness facet of dutifulness (p < 0.05).
• TT increased vulnerability, a facet of neuroticism (p < 0.05).
• Findings were derived from linear mixed-effect models comparing active and placebo intervention phases.

The adverse personality changes observed with hormone and testosterone therapy parallel personality changes seen in dementia.

• Both HT in women and TT in men produced changes in vulnerability and conscientiousness facets.
• Personality changes, like cognitive changes, are known to occur with dementia.
• The authors note that findings concerning the effects of HT on cognition and dementia are mixed, with some trials suggesting increased harm at older ages.
• This is described as a preliminary study, and no prior clinical trials had examined the effects of HT on personality traits.

The study used a randomized, double-blind, placebo-controlled cross-over design with a 3-month washout period between intervention phases.

• Each intervention phase (active hormone or placebo) lasted 3 months, with a 3-month washout period between phases.
• Participants were crossed over between active hormone intervention and identical placebo.
• Total sample was 51 participants (29 men, 22 women), all community-dwelling and cognitively normal.
• Mean participant age was 75.2 years.
• This was a secondary data analysis from two separate parent trials — one for menopausal HT in women and one for testosterone therapy in men.