The Neurobiology of Addiction

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)

Inside the brain:

Brian cells called neurons send chemical messages

Neurotransmitter - chemical messenger

Synapse - Space between neurons where neurotransmitters travel

The Brain’s 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

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)

When cocaine is present

Cocaine blocks the reuptake of dopamine

Synapse is flooded with dopamine, causing feeling of euphoria

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

Meth Brain Damage

Meth Brain Damage

The limbic region, involved in drug craving, reward, mood and emotion, lost 11 percent of its tissue. "The cells are dead and gone," Dr. Thompson said. Addicts were depressed, anxious and unable to concentrate.

The brain's center for making new memories, the hippocampus, lost 8 percent of its tissue, comparable to the brain deficits in early Alzheimer's. The methamphetamine addicts fared significantly worse on memory tests than healthy people the same age.

The faces of Meth

And finally…Meth Mouth

Meth users feel incredibly sexy because of the high

They actually deteriorate very quickly due to their fixation on the drug and its harmful effects