Despite being a CNS stimulant, the addiction and dependence liabilities of modafinil are considered low. The exact mechanisms of action of modafinil are not known, and it is believed that pharmacological profile of modafinil is different from that of the classical stimulants. Although modafinil shares biochemical mechanisms with stimulant drugs, it is less likely to have mood-elevating properties. The similarities in effects with caffeine are not clearly established. Unlike other stimulants, modafinil does not induce a strong subjective feeling of pleasure or reward, which is commonly associated with euphoria, an intense feeling of well-being. Euphoria is a potential indicator of drug abuse, which is the compulsive and excessive use of a substance despite adverse consequences. In comparison to classical stimulants, modafinil exhibits a low propensity for abuse, as it lacks significantly expressed pleasurable or euphoric effects. Albeit to a lower degree than classical stimulants, modafinil still produces psychoactive, euphoric, and subjective effects typical for abused stimulants.
Modafinil was not observed to promote overuse or misuse, even in people who have a history of cocaine addiction. Despite the initial belief that modafinil carried no abuse potential, emerging evidence suggests that it works at the same neurobiological mechanisms as other addictive stimulants. Consequently, there exists a potential risk of modafinil abuse, necessitating prudent consideration and caution when prescribing or using this medication. Modafinil exhibits a lower response on the amphetamine scale of the addiction research center inventory, suggesting reduced propensity for abuse compared to amphetamine.
The US Drug Enforcement Administration has classified modafinil as a Schedule IV controlled substance; the medicine is recognized for having valid medical uses with low addiction potential. The International Narcotics Control Board does not classify it as a narcotic or a psychotropic substance.