3.1.1 Humans
Males are significantly more likely to use and abuse androgenic anabolic
steroids (AAS) compared to females (Kanayama et al., 2010; Kanayama et
al., 2018; Wood, 2008). In humans, AAS abuse is often a precursor to the
abuse of other drugs, particularly opioids (Kanayama et al., 2003;
Skarberg et al., 2009; Kanayama et al., 2009a; Kanayama et al., 2009b).
Indeed, several studies have reported a relationship between admission
for opioid treatment and a prior history of AAS use (Trenton & Currier,
2005; Kanayama et al., 2009a; Ranjan et al., 2014), leading
investigators to conclude that AAS abuse increases the risk of opioid
addiction (Kanayama et al., 2018; Kanayama et al., 2003). Opioid use
also occurs prior to and concurrently with AAS abuse, suggesting that
opioid use also increases susceptibility to AAS abuse (GÄrevik & Rane,
2010; Wines et al., 1999; Ranjan et al., 2014; Skarberg et al., 2009;
McBride et al., 1996; Kindlundh et al., 1999). Collectively, such
findings suggest that opioid agonists and AAS may mutually enhance the
abuse liability of one another, and this may be particularly true in
men.