Anabolic-androgenic steroids and decision making: Probability and effort discounting in male rats.
Level 5 - mechanism / opinion, no new human data
Controlled animal research with no direct human data.
PubMed 25900595 · doi:10.1016/j.psyneuen.2015.03.023
What was done
Adolescent male Long-Evans rats received chronic treatment with high-dose testosterone (7.5 mg/kg) or vehicle control (13% cyclodextrin in water). Decision making was evaluated using two operant discounting paradigms involving choices between a small guaranteed reward (1 sugar pellet) and a larger reward (3 or 4 pellets): probability discounting (reward probability decreased: 100%, 75%, 50%, 25%, 0%) and effort discounting (required lever presses increased: 1, 2, 5, 10, 15 presses).
What was found
The abstract does not provide exact numerical values, effect sizes, or test statistics, but reports significant directional effects: - In probability discounting, testosterone-treated rats selected the large uncertain reward significantly less than vehicle controls. - In effort discounting, testosterone-treated rats selected the large high-effort reward significantly more than vehicle controls.
Why it matters
These findings suggest that anabolic-androgenic steroid exposure selectively alters reward evaluation in rats, increasing sensitivity to risk/uncertainty while decreasing sensitivity to the physical effort required to obtain rewards.
Limits
The abstract omits total sample size, group counts, exact statistical values, and effect sizes. The study is restricted to adolescent male rodents receiving a single dosing regimen, limiting direct generalizability to human steroid users, different age groups, female subjects, or other synthetic anabolic compounds.