Psychoactive Drugs

Types of Psychoactive Drugs

Depressants - alcohol, barbiturates, and opiates that reduce neural activity and slow body functions

Stimulants - caffeine, nicotine, cocaine, ecstasy, methamphetamine that excite neural activity and speed up body functions

Hallucinogens - psychedelics such as LSD that distort perceptions and evoke sensory images in the absence of sensory input

Depressants

Alcohol

• Acts as a disinhibitor – slows brain activity that controls judgement and inhibitions

• Slowed Neural Processing

  • Low doses slow sympathetic nervous system activity

  • Larger doses slow reactions, speech and skilled performance

    • Lead to accidents and violent crime

  • As blood-alcohol levels rise, judgment falters

• Memory Disruption

  • Heavy drinking can have long-term effects on brain and cognition

  • Binge drinking contributes to nerve cell death and impairs growth of synaptic connections

  • Blackouts – unable to recall people or events while intoxicated – caused partly from the way alcohol suppresses REM sleep

  • Alcohol use disorder – can shrink the brain – girls more susceptible due to lack of stomach enzymes

• Reduced Self-Awareness and Self-Control

  • Focus on arousing situations instead of thinking about normal inhibitions and future consequences

    • Explains drinking after a failure or sadness

• Expectancy Effects

  • Belief that alcohol affects behavior will allow it to affect behavior

    • Ex: After believing they consumed alcohol, men were more likely to report having strong sexual fantasies and feeling guilt free over those who were told they didn’t consume alcohol

Barbiturates