Anabolic steroids are the drugs related to the male sex hormone testosterone and have androgenic activity, or an ability to increase muscle mass and tone. Numerous drugs are available in this group, mostly illicit, as solutions for injection, although some are taken orally. These steroids include stanozolol, nandrolone, methenolone, metandienone, oxymetholone, and tenbolone to name but a few. These drugs can be taken as small doses of two or more steroids, larger doses in cycles lasting 1–3 months, or as ever increasing doses as demanded. The net effect is a larger buildup of muscle mass compared to a drug-free situation for a given amount of body building.
A well-recognized side effect associated with the use of anabolic steroids is the appearance of mood disorders, irritability, and aggression. Controlled studies in athletes show a significant number of steroid users reporting major mood disorders, including mania, hypomania, and major depression. Psychoses, delusions, aggressive, and violent behavior are also strongly associated with active steroid users. Reports of fits of anger, assault, and attempted murder are also linked to steroid use.
Personality profiles of men using anabolic steroids also show enhanced physical and verbal aggression and disinhibition.