Psychoactive Drugs

PSYCHOACTIVE DRUGS — NOTES

I. Scope of Substance Use in the U.S. (2002 Stats)

  • 54 million binge drinkers.

  • 16 million heavy daily drinkers.

  • 19.5 million current illicit drug users.

    • Most common: marijuana, then misused prescriptions.

  • 2 million cocaine users (567k crack users).

  • 1.2 million hallucinogen users (e.g., LSD, Ecstasy).

  • 166,000 heroin users.

II. How Psychoactive Drugs Work

Blood–Brain Barrier

  • Normally protects brain from chemicals.

  • Psychoactive drugs mimic natural neurotransmitters and slip through.

Neurotransmitter Effects

  • Drugs alter communication between neurons.

  • Two types:

    • Agonists: mimic or enhance neurotransmitter activity.

    • Antagonists: block or reduce neurotransmitter activity.

  • Results: altered consciousness, mood, perception, and behavior.

III. Categories of Psychoactive Drugs

1. Stimulants

Effect: Speed up the nervous system; increase alertness, euphoria.

Examples:

  • Nicotine

  • Caffeine

  • Amphetamines (speed, uppers)

  • Cocaine

Risks:

  • Heart strain or heart failure

  • Addiction

  • Paranoia

2. Depressants

Effect: Slow down the central nervous system; reduce anxiety, impair judgment.

Examples:

  • Alcohol

  • Barbiturates

  • Tranquilizers (Valium)

Risks:

  • Dangerous when combined with other drugs

  • Impaired coordination and reaction time

  • High overdose risk

3. Opiates

Effect: Powerful pain relief; intense euphoria; mimic endorphins.

Examples:

  • Heroin

  • Morphine

  • Codeine

Risks:

  • Most addictive drug category

  • Severe withdrawal

  • High overdose risk

4. Hallucinogens (Psychedelics)

Effect: Distort reality; cause vivid hallucinations.

Examples:

  • LSD (lab-made)

  • Peyote, mushrooms (natural)

  • Marijuana

Special Concept: Reverse Tolerance

  • Drug stays in body for weeks.

  • Future doses may require less drug to achieve same effect.

IV. Amphetamines and Methamphetamines

Amphetamines

  • Strong stimulants (“speed/uppers”).

  • Boost confidence, energy, aggression.

  • Lead to violent behavior.

  • After wearing off: depression crash.

Methamphetamines (Meth/Crank/Ice)

  • Synthetic, extremely addictive.

  • Illegally made with toxic chemicals.

  • Causes massive dopamine release.

  • Damages dopamine neurons long-term.

V. Barbiturates

  • Strong depressants used medically.

  • Sedative/hypnotic effect.

  • Highly addictive.

  • Dangerous if mixed with alcohol.

VI. Ecstasy (MDMA)

Effects:

  • Stimulant + hallucinogen hybrid.

  • Feelings of emotional closeness (“oneness”).

  • Jaw clenching, increased energy.

Major Risks:

  • Neurotoxic: destroys serotonin neurons.

  • Raises body temperature dangerously.

  • Can damage heart, kidneys, and muscles.

VII. Addiction Concepts in DSM-5

Tolerance

  • Need increasing amounts for same effect.

  • Example: needing 2–3 coffees instead of 1.

Withdrawal

  • Physical or psychological distress when stopping.

  • Alcohol withdrawal can include:

    • Fever

    • Seizures

    • Delirium

    • Death (in severe cases)

Psychological Dependence

  • Cravings and emotional need for the drug.

  • Can occur even without physical withdrawal.

VIII. Behavioral Addiction

DSM-5 includes one behavioral addiction:

Gambling Disorder

  • Only non-substance disorder classified as an addiction.

  • Symptoms:

    • Poor impulse control

    • Compulsive gambling despite consequences

    • Interference with daily life

Possible future additions being studied:

  • Internet gaming disorder

KEY AP PSYCH TAKEAWAYS

✔ Agonists mimic neurotransmitters; antagonists block them.
✔ Stimulants speed up CNS; depressants slow it down; opiates mimic endorphins; hallucinogens distort reality.
✔ Meth and cocaine intensify dopamine activity.
✔ Tolerance = need more. Withdrawal = symptoms when stopping.
✔ Only gambling disorder is officially a behavioral addiction in DSM-5.
✔ Hallucinogens can show reverse tolerance.