Psychoactive Drugs and Substance Use Disorder

Tolerance and Addiction

• Substance Use Disorder

  • Continued craving and use despite significant disruptions and/or physical risks.

• Psychoactive Drugs

  • Chemicals that alter perceptions and moods.

• Tolerance

  • Diminishing effect with regular use of a drug, leading to the need for larger doses to achieve the same effect.

• Neuroadaptation

  • The brain adapts to offset the drug's effect on the user's brain chemistry.

• Addiction

  • Compulsive craving of certain behaviors (e.g., gambling) despite known adverse consequences.

• Withdrawal

  • Discomfort and distress that follow discontinuing an addictive drug or behavior.

Types of Psychoactive Drugs

Depressants

• General Overview

  • Reduce neural activity and slow body functions.

• Alcohol

  • Acts as a disinhibitor, controlling brain activity related to judgment and inhibitions.

  • Effects:

  • Slows neural processing

  • Impairs skilled performance

  • Disrupts memory and cognition

  • Contributes to nerve cell death and inhibits new nerve cell growth

  • Long-term excessive drinking can lead to alcohol use disorder, characterized by tolerance, withdrawal, and a drive to continue problematic use.

• Expectancy Effects

  • People behave according to their beliefs about alcohol's effects on social behavior.

• Barbiturates

  • Suppress central nervous system activity; reduce anxiety but impair memory and judgment.

  • Examples: Nembutal, Seconal, Amytal.

• Opiates

  • Opium and its derivatives (morphine, heroin); depress neural activity, temporarily lessening pain and anxiety.

  • With repeated use, the brain may stop producing endorphins, leading to withdrawal and overdose.

Stimulants

• General Overview

  • Excite neural activity and speed up body functions.

• Amphetamines

  • Cause sped-up body functions, increase energy and mood changes.

• Caffeine & Nicotine

  • Highly addictive psychoactive drugs.

  • Withdrawal Symptoms for Nicotine: insomnia, anxiety, irritability, distractibility, and craving.

  • Effects include diminished appetite, boosted alertness, and increased mental efficiency.

• Cocaine

  • Produces temporary euphoria and increased alertness.

  • Depletes neurotransmitters (dopamine, serotonin, norepinephrine).

  • May lead to emotional disturbances, suspiciousness, and could cause convulsions or cardiac arrest.

• Methamphetamine

  • Stimulates central nervous system, increasing body functions and energy.

  • Long-term effects include irritability, insomnia, and reduced baseline dopamine levels.

• Ecstasy (MOMA)

  • A synthetic stimulant and mild hallucinogen; produces euphoria but has short-term health risks.

  • Negative effects include dehydration, overheating, and impairment of serotonin-producing neurons.

Hallucinogens

• General Overview

  • Distort perceptions and evoke sensory images without sensory input.

• LSD

  • A powerful hallucinogen, can cause euphoria and panic.

  • Effects include geometric forms, meaningful images, or a sense of detachment, similar to near-death experiences.

• Marijuana (THC)

  • Triggers various effects including mild hallucinations and euphoria.

  • Can impair motor coordination, perceptual skills, and disrupt memory formation, particularly in young people.

  • Uses: Legalized for medical scenarios (e.g., relief of pain associated with AIDS, cancer, glaucoma).