Widespread illicit anabolic steroid use has recently been reported. A review of available evidence suggests that elevations of serum levels of steroid hormones, including anabolic steroids, have profound psychological effects. Long-term, high-dose anabolic steroid use may lead to a preoccupation with drug use, difficulty stopping despite psychological side effects, and drug craving. Reductions in serum levels of steroid hormones appear to result in acute hyperadrenergic withdrawal symptoms that respond to steroid replacement or to agents that also ameliorate withdrawal symptoms in alcohol and opioid dependence. A delayed depression syndrome when serum steroid levels drop precipitously has been reported that appears similar to that observed in withdrawing cocainedependent individuals. We conclude that a proportion of anabolic steroid abusers may develop a previously unrecognized sex steroid hormone—dependence disorder and that treatment should be based on research into steroid effects on opioid and aminergic neurotransmission systems and relapse prevention.