6. Psychopharmacology

Drug Nomenclature

• Chemical name: molecular structure. • Generic name: legal/official name (e.g., diazepam). • Trade name: brand (e.g., Valium).

Drug Scheduling (DEA)

• Schedule I: high abuse, no medical use (e.g., heroin, LSD). • Schedule II: medical use, high abuse (e.g., morphine, methamphetamine). • Schedule III–V: decreasing abuse potential.

Phases of Pharmacokinetics (ADME)

• Absorption, Distribution, Metabolism, Excretion.

Pharmacokinetics vs. Pharmacodynamics

• Pharmacokinetics: what the body does to the drug. • Pharmacodynamics: what the drug does to the body.

Agonism vs. Antagonism

• Agonist: enhances neurotransmission (direct or indirect). • Antagonist: blocks or decreases neurotransmission.

Major Drugs and Mechanisms

• Nicotine: stimulates acetylcholine receptors; increases dopamine release. • Cocaine: blocks reuptake of dopamine, norepinephrine, and serotonin. • SSRIs: block serotonin reuptake; increase synaptic 5-HT. • Naloxone: opioid antagonist; reverses overdoses. • Alcohol: enhances GABA, inhibits glutamate; increases dopamine. • Marijuana (THC): activates CB1 receptors; decreases neurotransmitter release.

Terminology

• Addiction: compulsive drug use despite consequences. • Dependence: physiological adaptation; withdrawal upon cessation. • Substance Use Disorder (SUD): problematic pattern of use with impaired control.

Brain Reward Circuit

• Involves ventral tegmental area (VTA) and nucleus accumbens (NAc); dopamine release underlies reward and craving.

Dopamine

• Key neurotransmitter in reward, motivation, and addiction; reduced receptor levels linked to craving.