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Teen on Couch Passed Out from Drug Abuse
Drugs of abuse work on different neurotransmitter systems in the brain, but they all act directly or indirectly on the brain's reward (mesolimbic) system and on the amygdala, flooding the reward circuit with dopamine and other neurotransmitters. The brain adjusts to these overwhelming surges of dopamine and other neurotransmitters by producing less of the neurotransmitters, or by reducing the number of receptors that can receive and transmit signals. Drug abusers' ability to experience pleasure without the drug is reduced, and they begin to feel lifeless and depressed.