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Neural mechanisms of motivation and addiction - Coggle Diagram
Neural mechanisms of motivation and addiction
Current Issues in Addiction Research
Addiction Is Psychologically Complex
Drug addicts differ psychologically from healthy controls
Make poor decisions
Engage in excessive risk taking
Have deficits in self control
Addiction Is a Disturbance of Decision Making
Primary symptom of addiction is a disturbance of decision making
Addiction Is Not Limited to Drugs
Inability to refrain from a behavior despite its adverse effects
Overeating
Compulsive gambling
Compulsive sexual behavior
kleptomania (compulsive shoplifting)
Compulsive shopping
Share some brain mechanisms with drug addiction
Addiction Involves Many Neurotransmitters
Role for glutamate
Prefrontal glutaminergic neurons that project into the nucleus accumbens.
Endogenous opioids, norepinephrine, GABA, and endocannabinoids
Not limited only to dopamine
Brain Structures That Mediate Addiction: The Current View
Initial Drug Taking
Similar to any pleasurable activity
Mesocorticolimbic pathway (nucleus accumbens playing a key role)
Interactions of nucleus accumbens with three other areas of brain:
Amygdala (coordinate the positive or negative emotional reactions to the drug taking)
Hippocampus and related structures (information about previous relevant experiences)
Prefrontal lobes (decision to take a drug)
Change to Craving and Compulsive Drug Taking
Several changes in the brain’s responses:
As addiction develops, striatal control of addiction spreads from
Nucleus accumbens (i.e., the ventral striatum) to the dorsal striatum (plays a role in habit formation and retention)
At the same time, role of the prefrontal cortex in controlling drug-related behaviors declines
Stress circuits in the hypothalamus begin to interact with the dorsal striatum
Relapse
3 factors to trigger relapse:
Priming doses of the drug
Drug associated cues
Stress
Each cause is mediated by interaction of a different brain structure with the striatum
Prefrontal cortex mediates priming-induced relapse
Amygdala mediates conditional cue-induced relapse
Hypothalamus mediates stress-induced relapse.