The Neurobiology of Addiction

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The Neurobiology of Addiction
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Physical vs. Psychological

• Physical addiction actually changes structure of
  brain
• Brain needs drug for normal function
• Permanent brain damage can occur
• Can begin after 1st use

• Users think they need it, but no true chemical
  need
• Bad habit, socially reinforced (marijuana,
  caffeine)

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Inside the brain

• Brain cells called neurons send chemical messages
• Neurotransmitter - chemical messenger
• Synapse - Space between neurons where
  neurotransmitters travel

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The Brains reward center

• Reward center is region of brain that responds to
  sensations of pleasure
• Dopamine naturally stimulates the reward center
• Many drugs simulate this process

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When things are going well

• Neurotransmitter Dopamine is released, carries
  message, then re-enters original neuron for reuse
• Responsible for feelings of pleasure
• Designed to reinforce positive behavior (eating,
  sex, altruism, learning)

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When cocaine is present

• Cocaine blocks the reuptake of dopamine
• Synapse is flooded with dopamine, causing feeling
  of euphoria

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Long-term Damage?

• Long-term drug use results in loss of dopamine
  receptors
• Users report constant depression, sadness,
  feelings of hopelessness
• Need more and more of the drug just to feel
  normal
• Potential for high is gone