Chapter 10: Substance-Related, Addictive, and Impulse-Control Disorders

Substance use disorders involve the compulsive consumption of psychoactive substances despite harmful consequences, manifesting along a severity spectrum from mild to severe according to diagnostic criteria. Key features include tolerance development, withdrawal symptoms upon cessation, and continued use despite awareness of negative outcomes. The chapter categorizes psychoactive substances by their physiological effects: depressants reduce central nervous system activity and carry risks of physical dependence and organ damage; stimulants elevate dopamine activity and can trigger paranoia or cardiovascular complications; opioids bind to endorphin receptors producing analgesia and euphoria but present extreme overdose danger; cannabis alters perception and may precipitate psychotic symptoms; hallucinogens distort sensory processing with variable dependence potential; and other substances including inhalants, anabolic steroids, and designer drugs carry distinct neurological and systemic risks. The chapter integrates biological explanations such as genetic vulnerability and dopamine system dysfunction with psychological mechanisms including positive and negative reinforcement, and social factors including peer influence and environmental stress. Treatment approaches encompass pharmacological interventions using agonist substitution, antagonist medications that block drug effects, and aversive conditioning; alongside psychosocial interventions including cognitive-behavioral therapy focused on trigger identification and craving management, contingency management utilizing incentive-based reinforcement, motivational enhancement therapy targeting commitment to behavior change, and peer-support models. Impulse-control disorders represent a related category involving persistent difficulty resisting harmful urges despite awareness of consequences. The chapter addresses intermittent explosive disorder involving uncontrolled aggression episodes, kleptomania involving compulsive theft driven by emotional relief rather than material need, and pyromania involving fire-setting urges linked to tension reduction. These conditions respond to cognitive-behavioral intervention, pharmacological treatment targeting underlying mood dysregulation, and emotion-regulation training addressing the functional role of impulsive behavior.