Swedish researchers have found that there could well be a link between the use of anabolic steroids and antisocial behaviour.
Anabolic steroids are drugs related to male sex hormones and can be taken through injections or orally; many athletes, bodybuilders and others, both male and female, use steroids without a prescription to build muscle bulk and strength in order to look better.
Steroids can cause serious side effects, including liver cancer, and kidney disease.
Apparently non-prescription steroid use has been linked previously to a number of psychiatric conditions and changes in behaviour and there have been reports of groups such as bodybuilders using anabolic androgenic steroids where hypomania or manic episodes, depression or suicide, psychotic episodes and increased aggressiveness and hostility have been experienced.
Dr. Fia Klötz of Uppsala University in Sweden, and colleagues studied the associations between criminality and steroid use in 1,440 Swedish residents tested for the drugs between 1995 and 2001.
They found that those who tested positive for steroid use were about twice as likely to have been convicted of a weapons offence and one and a half times as likely to have been convicted of fraud.
It appears that the use of anabolic steroids is associated with a lifestyle involving crime, including weapons offences and fraud, but did not appear to be associated with violent crimes or crimes against property.
The authors say aggressiveness appears to occasionally trigger violent behaviour, sometimes even including homicide and steroid use is linked to extreme mood swings, impulsiveness, depression, paranoid jealousy, extreme irritability, delusions and impaired judgment.
The study involved individuals whose average age was 20 who were referred from inpatient and outpatient clinics, including substance abuse facilities, as well as police and customs stations.
Of those screened, 241 tested positive and 1,199 tested negative and served as controls.
The criminal records of all the subjects were scrutinised and offences for which participants were convicted were divided into five categories: violent crime, including homicide, assault and robbery; weapons offences; property crimes, including theft and receiving stolen goods; fraud; and sexual offences.
It was found that those who tested positive for steroid use were about twice as likely to have been convicted of a weapons offence and one and a half times as likely to have been convicted of fraud.
There was however no difference in the rate of violent crimes, sexual offences or crimes against property between those who tested positive for steroids and those who tested negative.
The researchers say that when individuals who came from substance abuse centers were excluded, the association between steroid use and weapons offences remained significant.
They believe a possible explanation might be that criminals involved in crimes such as armed robbery or crime related debt recovery, are at an advantage from being muscular and having a heavy build.
Steroids are generally associated with violent outbursts of anger and impulsive behaviour, but the study demonstrates that they may also be linked to crimes involving preparation and advance planning.
Men who use anabolic steroids can experience a shrinking of the testicles, a lower sperm count, raise prostate cancer risk and infertility and baldness.
Women may have increased facial hair growth, male-pattern baldness, menstrual problems and a deeper voice.
Steroids can also stunt the growth of adolescents.
However, the authors say more research needs to be done to assess the motives behind and effects of steroid use by criminals.
The research appears in the November issue of Archives of General Psychiatry.