Low testosterone levels linked to depression in older men

By Andrew Czyzewski
14 March 2008
Arch Gen Psychiatry 2008; 65: 283-289

Older men who experience clinical depression have lower levels of free testosterone than their peers without depression, a study has demonstrated.
The finding could explain the hike in depressive symptoms among men older than 65 years, say Australian researchers, who speculate that these men may benefit from systemic screening of testosterone levels and supplementation with exogenous preparations of the hormone.
Women are more likely to be depressed than men until the age of 65 years, when the gender differences almost disappear, observe Osval Almeida (University of Western Australia, Perth) and colleagues.
Observational studies suggest that gonadal corticosteroids may be partly responsible for this phenomenon, but data to support a potential role for testosterone in the modulation of mood remain scant.
To investigate, the researchers mailed a questionnaire to 3987 community-dwelling men aged 65 years or older.
In addition to providing information on clinical and demographic factors, participants were asked to complete the 15-item Geriatric Depression Scale (GDS-15), where a total score of 7 indicates clinically significant depressive symptoms.
Blood samples were taken from all participants and serum concentrations of free testosterone and testosterone bound to sex hormone-binding globulin were quantified.
As reported in the Archives of General Psychiatry, 5.1% of the men were experiencing depression at the time of the study.
Men with total testosterone concentrations in the lowest quintile (<308 ng/dl) were 1.55 times more likely to be depressed than men with testosterone concentrations in the highest quintile (≥556ng/dl), after adjusting for physical morbidity.
This effect was more pronounced when considering free testosterone levels, such that men in the lowest quintile (<6 ng/dl) were 2.71 times more likely to be depressed than men with free testosterone concentrations in the highest quintile (≥10 ng/dl).
Since the present study was unable to determine a direct causal relationship between depression and testosterone levels, the researchers call for a randomized clinical trial to determine if testosterone has a protective role.
If such an effect is confirmed, Almeida et al say that systemic screening of free testosterone may contribute to the successful treatment of hypogonadal older men with depression.
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