Drug Addiction

No# ppt: absinthe1 Picasso "Absinthe Drinker" Pablo Picasso (1910)

What is Addiction? Defined by tolerance, withdrawal, & compulsion Involves a person's heightened and habituated need for a substance (or engagement in a particular behavior) It causes discomfort or suffering that results from discontinuation of its use Addicted individuals will sacrifice things and people they value (to the point of self-destruction) for their addiction.

Drug Addiction Drug addiction is conceptualized as a chronic relapsing syndrome that moves from an impulse control disorder involving positive reinforcement to a compulsive disorder involving negative reinforcement

KoobG/NP/dia3/031902jh From: Koob GF, Alcohol Clin Exp Res, 2003, 27:232-243.

Drug Addiction in Context Prevalence of Addiction Addiction Across Cultures Heredity Influences in Addiction Environmental Drug use is a learned coping strategy in response to past learning and current life events Diathesis/Stress Model Genetic predisposition combined with environmental factors

Causes of Addiction: Personality-Heredity Particular personality traits predispose one to addiction Sensation seeking The seeking of novel experiences and sensations Impulsivity An inability to delay gratification The preference of immediate small rewards over large, but more delayed rewards Decision-making without consideration of potential negative consequences

Support for Personality Theory of Drug Abuse Why is this relevant? If we can identify factors that place individuals at an increased risk for drug use/abuse, then we may be able to target these groups for prevention Treatment based on this theory has yet to be developed in spite of evidence from research

Causes of Addiction: Environmental Behavioral Classical Conditioning: Stimuli related to the addictive behavior become paired with the behavior Further contact produces conditioned response Operant Conditioning: Past addictive behavior produced positive consequences Future use in presence of discriminative stimuli Addictive behavior is more rewarding than alternatives Expectancy Theory From past experience with substances, one develops an expectancy about what the substance can do for them Self-medication hypothesis

Support for Environmental Explanations of Addiction Untreated Heroin recovery (Robins, 1975) Research on 451 Vietnam veterans who had been addicted to narcotics in during the war Only 14 percent became re-addicted after their return Environmental cues for addiction no longer active Heroin overdose In the presence of heroin cues, body has compensatory reaction (Falk, 1983) If drug taken out of typical environment, body does not prepare for drug that comes If no drug taken in typical environment, body prepares for drug that never comes

Causes of Addiction: Diathesis/Stress Model Certain people, due to a variety of biologically-based factors (genetics, neurocognitive functioning, stress response), may be predisposed (diathesis) to developing an addiction to something, be it alcohol, heroin, gambling, sex, shopping, or on-line computer services. They could go through their entire lives never developing any kind of addiction. On the other hand, if the right stressor, or combination of stressors, affects the person at a critical time, the person may be more inclined to develop an addiction.

Tracing the Neurobiological Roots of Addiction Neural Circuits Involved in Establishing Addiction Role of the nucleus accumbens Role of the orbitofrontal cortex

Figure 11. 1 Extended amygdala Figure 11.1 Extended amygdala. Lambert and Kinsley: Clinical Neuroscience, Second Edition Copyright © 2011 by Oxford University Press, Inc.

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Figure 11. 3 Two dopamine pathways in the brain Figure 11.3 Two dopamine pathways in the brain. Lambert and Kinsley: Clinical Neuroscience, Second Edition Copyright © 2011 by Oxford University Press, Inc.

Tracing the Neurobiological Roots of Addiction (cont.) Neurochemistry of Addiction Dopamine: Primary fuel of addiction Potential role of acetylcholine

Tracing the Neurobiological Roots of Addiction (cont.) Craving Response Craving as a conditioned response Neural components of the craving response

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