We evaluated 45 men, of whom 31 reported a history of AAS use and 14 denied use. However, one man was strikingly muscular, yet denied any history of AAS or other performance- or image-enhancing drug use. Both the interviewer and the cognitive testers independently suspected that this man had actually used AAS, but had not disclosed this information. We therefore excluded his data, leaving 13 nonusers for analysis. The 31 AAS users reported a lifetime duration of AAS use ranging from 8-640 weeks. Twenty-two of these men met our definition of “long-term AAS users,” in that they reported at least two years of lifetime use. AAS users and nonusers were similar in mean age and years of lifting weights, but nonusers reported substantially more years of education ().
Demographic Features of AAS Users and Nonusers
Comparing long-term users with nonusers on the test results (), we found no significant differences between groups on Choice Reaction Time and Rapid Visual Information Processing, suggesting that motor speed, alertness, and ability to maintain attention were not associated with AAS exposure. Verbal Recognition Memory also revealed no significant differences between groups on number of words generated on immediate free recall, errors on immediate recognition, and errors on delayed recognition of the 18 words. However, on immediate Pattern Recognition Memory, long-term users committed significantly more errors than nonusers when attempting to recognize patterns that they had previously seen. In the delayed presentation of this test, long-term users also committed somewhat more errors than nonusers, but this difference did not reach significance. On Paired Associates Learning, a test also tapping visuospatial memory, long-term users again performed significantly more poorly than nonusers, both in adjusted total errors on the full test up through the stage presenting eight patterns, and in adjusted total errors only up through the stage of six patterns. Finally, examining the two measures for which we possessed z-scores, the user and nonuser groups showed no clinically significant difference in sensitivity to the target on Rapid Visual Information Processing (estimated mean difference in z-scores [95% confidence interval]: 0.18 [-0.77, 1.12]), but a marked difference in errors on immediate Pattern Recognition Memory (estimated mean difference: 0.89 [0.06, 1.71]). To appreciate the magnitude of this latter effect, one could standardize this result to a mean of 100 and standard deviation of 15, in the manner of the Wechsler Adult Intelligence Scale (Wechsler, 1939
). On this hypothetical “visuospatial IQ” scale, long-term AAS users scored an average of 13.4 points below nonusers.
Cognitive Test Performance in Long-Term AAS users vs. Non-users
The second primary analysis, assessing associations between lifetime AAS dose and the outcome variables among all 31 AAS users, yielded findings generally consistent with those of the first. Specifically, Choice Reaction Time, Rapid Visual Information Processing, and Verbal Recognition Memory scores showed little or no significant association with AAS dose on regression analyses (). However, the number of errors on Pattern Recognition Memory, both in the immediate and delayed presentations (, panels A and B), was strongly and significantly associated with lifetime AAS dose. Paired Associates Learning showed a slight but nonsignificant association with lifetime AAS dose ( panel C). These findings remained virtually identical on repeat analyses using the nonparametric methods described above. Looking at the tests with available z-scores, Rapid Visual Information Processing showed essentially no correlation with lifetime AAS dose (estimated change in z-scores per 100g of lifetime AAS use: −0.01 [−0.12, 0.10]), but z-scores on Pattern Recognition Memory declined markedly with increasing lifetime AAS exposure (change in z-scores per 100g of lifetime AAS use: −0.13 [−0.22, −.05]; change in z-scores per year of lifetime AAS use: −0.11 [−0.21, −0.02]). To illustrate the magnitude of this latter effect on our hypothetical “visuospatial IQ” scale described above, AAS users showed a 1.7-point decline in visuospatial IQ for every year of continued AAS use.
Associations of Cognitive Test Performance with Lifetime AAS Dose in 31 AAS Users
Figure 1 Association between lifetime dose of anabolic-androgenic steroids (AAS) and cognitive test measures in 31 AAS users. (A) Pattern Recognition Memory Processing, errors on immediate presentation: r = 0.54; p =0.002. (B) Pattern Recognition Memory Processing, (more ...)
The sensitivity analyses suggested that the findings were quite stable. We first repeated our analyses while excluding the eight individuals (seven AAS users and one nonuser) who displayed one or more of the following attributes that might affect cognitive performance: 1) having discontinued AAS within the last six months, thus possibly precipitating AAS-withdrawal hypogonadism (Tan and Scally, 2009
); 2) history of past polydrug dependence (involving stimulants, cocaine, sedative-hypnotics, opioids, and/or cannabis); 3) consumption of a psychoactive drug of abuse or prescription sedative medication within the past 24 hours; and 4) history of head injury with prolonged loss of consciousness. In these analyses, all results remained little changed, with most coefficients remaining within 15% of their original values. Sensitivity analyses comparing the 18 current AAS users with the 13 past users, while adjusting for lifetime AAS dose, age, and education, showed no suggestion of differences in cognitive performance. Similarly, no suggestion of differences was found when comparing the 19 AAS users reporting a history of using any additional performance- or image-enhancing drugs (e.g., human growth hormone, insulin, etc.) with the 12 users who had not. We also considered that weightlifters sometimes use stimulants (e.g. amphetamine, methamphetamine, or clenbuterol) to improve performance or body appearance (Hildebrandt et al., 2011
), and that these drugs might affect cognition. However, upon exploring this possibility, we found that no participant reported use of an amphetamine derivative currently or within two weeks prior to evaluation, and only one reported current use of clenbuterol.
Finally, upon reanalyzing the results of the two visuospatial tests while adjusting for NART scores as opposed to years of education, differences between long-term AAS users and nonusers were slightly attenuated on both tests, with adjusted mean differences reduced to about two thirds of their previous values on most measures. However, on associations between the test measures and lifetime AAS dose, the coefficients remained virtually identical, and the p-values remained unchanged or slightly decreased with the NART adjustment.