Figure 1.
A proposed theoretical model showing three hypothesized mechanisms by which anabolic-androgenic steroid (AAS) dependence may develop. Note that hypothesized predisposing factors are not assumed to be exclusively premorbid traits; as discussed in the text, evidence suggests that the association between these factors and AAS dependence may well be bidirectional in each case, in that AAS use may further exacerbate a premorbid trait. For example, the “impulsive delay-discounting risk-taking endophenotype” likely predisposes to AAS use as well as to conduct disorder and other forms of substance abuse. However, evidence suggests that AAS exposure may exacerbate impulsive and risk-taking symptoms by further increasing sensitivity to reward and decreasing sensitivity for punishment. These hypothesized bidirectional mechanisms are not shown in the figure for reasons of clarity.