Substance-Induced Mental Disorders

Comorbidity is a condition describing the presence of two or more diagnosable conditions happening, either at the same time or having a close temporal relationship, to the same individual. This is usually more focused on the presence of psychological/psychiatric problems and associated polydrug use and misuse. This chapter will try to identify and clarify the nature and relationship of the different avenues of clinical presentations presenting as substance-induced mental disorders. They include: Substance use and withdrawal from substances may lead to psychiatric syndromes or symptoms. Intoxication and dependence may produce psychological symptoms. Substance use exacerbating or altering the course of preexisting mental disorder. A primary mental disorder precipitated by a substance use disorder, which may lead to psychiatric syndromes. Although there are several different classification schemes for psychoactive drugs (pharmacological, legal, medical), the most common organization is based on their effect on behavior and cognition. According to this scheme, psychoactive drugs will be classified into three broad categories: (1) sedatives, (2) stimulants, and (3) hallucinogens. Substance-induced mental disorders will be described on the basis of this classification in this chapter.