Research suggests that GHB itself may be a neurotransmitter. The predominant effects of GHB are sedative, though GHB can produce a wide range of pharmacological effects depending on the dose. At lower doses GHB can relieve anxiety and produce relaxation. However, as the dose increases, the sedative effects result in sleep and eventual coma or death. Research also shows that GHB increases dopamine levels in the striatum of the brain.
Dopamine is a neurotransmitter that is intimately involved in reward and pleasure.
We have come to believe that the ability to increase brain dopamine levels is a common characteristic of most drugs of abuse. GHB also stimulates the release of growth hormone from the anterior pituitary gland. Plasma levels of growth hormones rise quickly and steadily after administration of GHB, which probably accounts for the popularity of GHB among some bodybuilders. Abuse liability determinations, simply put, assess pharmacological and behavioral effects of drugs relative to known drugs of abuse, as well as their consequences. It is a way for scientists to assess the likelihood that a drug will be abused.