1. Drug Addiction

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

3. 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.

4. 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

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

6. 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

7. 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

8. 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

9. 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

10. 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

11. 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.

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

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

14. No number scan.tif

15. No number scan.tif

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

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

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

19. End
Next…neuroanatomy