However, subcutaneous pellet implants of progesterone were later studied as a form of birth control in women in the 1980s and early 1990s, though no preparations were ultimately marketed.Aqueous suspensions of progesterone crystals for intramuscular injection were first described in 1944. These preparations were on the market in the 1950s under a variety of brand names including Flavolutan, Luteosan, Lutocyclin M, and Lutren, among others. Aqueous suspensions of steroids were developed because they showed much longer durations than intramuscular injection of steroids in oil solution. However, local injection site reactions, which do not occur with oil solutions, have limited the clinical use of aqueous suspensions of progesterone and other steroids. Today, a preparation with the brand name Agolutin Depot remains on the market in the Czech Republic and Slovakia. A combined preparation of progesterone, estradiol benzoate, and lidocaine remains available with the brand name Clinomin Forte in Paraguay as well. In addition to aqueous suspensions, water-in-oil emulsions of steroids were studied by 1949, and long-acting emulsions of progesterone were introduced for use by intramuscular injection under the brand names Progestin and Di-Pro-Emulsion (with estradiol benzoate) by the 1950s. Due to lack of standardization of crystal sizes, crystalline suspensions of steroids had marked variations in effect.
This is suggestive of two different forms, one associated more with impulsive behavior and emotional dysregulation, and the other with predatory aggression and affective disturbance, of the disorder.Various other gene candidates for ASPD have been identified by a genome-wide association study published in 2016. Several of these gene candidates are shared with attention-deficit hyperactivity disorder, with which ASPD is comorbid. Furthermore, the study found that those who carry four mutations on chromosome 6 are 50 percent more likely to develop antisocial personality disorder than those who do not. Physiological
Hormones and neurotransmitters
Traumatic events can lead to a disruption of the standard development of the central nervous system, which can generate a release of hormones that can change normal patterns of development. Aggressiveness and impulsivity are among the possible symptoms of ASPD. Testosterone is a hormone that plays an important role in aggressiveness in the brain. For instance, criminals who have committed violent crimes tend to have higher levels of testosterone than the average person. The effect of testosterone is counteracted by cortisol which facilitates the cognitive control of impulsive tendencies.One of the neurotransmitters that has been discussed in individuals with ASPD is serotonin, also known as 5HT.