Study Notes on Drugs, Addiction, and the Brain

Drugs and the Brain

• Drugs, addiction impact brain and central nervous system (CNS).

Central Nervous System Overview

• Composed of brain and spinal cord.

• Brain made up of billions of neurons communicating via electrical and chemical signals.

Key Brain Functions

• Different regions govern judgment, movement, reward, memory, and pain perception.

Neuronal Pathways

• Sensory neurons detect pain, sending signals through the spinal cord to the brain.

• Neurons consist of soma, axon, dendrites, and terminal branches.

Neurotransmitters in Addiction

• Key to brain function; transmit impulses between neurons.

• Drugs can create pleasurable feelings, leading to positive reinforcement and habitual use.

Dependence and Withdrawal

• Dependence develops from repeated drug use; neurons adapt to drug presence.

• Withdrawal can lead to serious physiological reactions, varying by substance.

Drugs and Mortality

• Tobacco, alcohol, and opioids are the deadliest substances in the US, causing hundreds of thousands of deaths.

Brain Structures Affected by Drugs

• Prefrontal lobes (executive function), limbic system (emotions), and brain stem (survival instincts).

Limbic System Functions

• Hippocampus (memory), amygdala (emotion/aggression), hypothalamus (regulates bodily functions).

Effects of Substances on the Brain

• Drugs affect emotional processing, motivation, and sensitivity to pleasure.

• Brainstem crucial for impulsive reactions and reward circuits.

Brain Development and Vulnerability

• Cerebral cortex matures last, making adolescents more susceptible to drug use.