7.3

Overview of Psychoactive Substances

• Psychoactive substances impact consciousness and alter thoughts, emotions, and behaviors.

• Examples include caffeine, alcohol, cannabis, and psychedelics.

• Interactions with the brain can be complex and risk-laden.

Review of Emotional Theories

• Review basic concepts of emotion (constructed theory vs. basic emotion theory).

  • Constructive theory (Lisa Feldman Barrett): Emotions are social constructs stemming from biology, learning, and context.

  • Basic emotion theory (Paul Ekman): Emotions are constant across cultures and innate.

Psychoactive Substances: Definitions

• Chemicals affecting consciousness, changing cognition, mood, and behavior.

• Categories include sedatives, opioids, stimulants, dissociatives, psychedelics.

Scientific Mechanisms

• Neurotransmitters: Key molecules in brain signaling.

  • Excitatory: Glutamate

  • Inhibitory: GABA

  • Other key neurotransmitters include Dopamine, Serotonin, Endocannabinoids, Adenosine, Norepinephrine, Endorphins.

  • Receptors: Ionotropic (instant, fast) vs Metabotropic (slower, prolonged).

• Agonists vs. Antagonists:

  • Agonists activate receptors; antagonists block them.

Substance Categories

1. Sedatives and Hypnotics:

   • Slow CNS function.

   • Examples: Xanax, alcohol, Ambien.

   • Mechanism: Increase GABA's inhibitory effects.

   • Risks: Dependence, tolerance, overdose dangers (respiratory depression).

2. Opioid Analgesics:

   • Pain relief by mimicking endorphins.

   • Examples: Oxycontin, heroin

   • Mechanism: Bind to mu-opioid receptors, disinhibit dopamine release leading to euphoria.

   • Risks: High addiction potential, fatal overdoses, contributing to the opioid crisis.

3. Stimulants:

   • Increase arousal and focus.

   • Examples: Caffeine, cocaine, amphetamines.

   • Mechanism: Varies:

     • Caffeine: Antagonizes adenosine receptors, leading to increased excitability.

     • Cocaine: Blocks dopamine transporters, increasing synaptic dopamine.

     • Amphetamines: Reverse dopamine transporters, releasing more dopamine.

   • Risks: Anxiety, insomnia, potential for psychosis.

4. Dissociatives:

   • Alter perception and create detachment.

   • Examples: Ketamine, PCP.

   • Mechanism: NMDA receptor antagonism reduces excitatory signaling.

   • Risks: Cognitive impairment, cardiovascular issues.

5. Psychedelics:

   • Profoundly alter perception and self-identity.

   • Examples: Psilocybin, LSD, DMT, cannabis.

   • Mechanism: Agonism of serotonin-2A receptors, impacting the Default Mode Network (DNN) for ego dissolution.

   • Risks: Bad trips, mental health triggers, lasting perceptual disturbances (HPPD).

Therapeutic Potential of Psychoactive Substances

• MDMA: Assisting therapy for PTSD.

• Psilocybin: Potential for treating depression and anxiety.

• Ketamine: Rapid antidepressant effects, promotes neuroplasticity.

• Cannabis: Medical benefits but risks of exacerbating mental health problems.

Societal Implications

• Different legal frameworks (prohibition vs. decriminalization).

• Ongoing opioid crisis reshaping regulations; focus on addiction as a public health issue.

• Harm reduction strategies to minimize substance risks.

• Reevaluation of drug views as society evolves; blurring lines between medicine and recreation.

Conclusion and Reflection

• Complexity of psychoactive substances and their multifaceted impact necessitate careful consideration of their biological, psychological, and societal aspects.

• Encouragement for personal reflection on the implications of substance use and regulation.