8 Psychopharmacology

Study Guide on Drugs and Pharmacology

Goals for Today's Lesson

  • Understanding drugs, their types, and basic pharmacology

  • Mechanisms of altering synaptic communication

  • Major drug categories: stimulants, opiates, alcohol, etc.

  • Concepts of addiction and its theories

  • Brain mechanisms of reward focusing on dopamine

  • Overview of medications to combat substance abuse

What is a Drug?

  • Definition: A substance (excluding food) that modifies body function.

  • Psychoactive Drugs: Affect psychological functions, leading to anxiety relief, hallucinations, and euphoria.

Naming of Drugs

  • Chemical Name: e.g. 7-chloro-1,2-dihydro-1-methyl-3phenyl-2H-1,4-benzodiazepin-2-1.

  • Generic Name: Official name (e.g., diazepam).

  • Trade/Brand Name: Capitalized name (e.g., Valium).

  • Street Name: Informal names (e.g., "yellow/blue V's").

Classification of Drugs

  • By Drug Effects on Behavior:

    • Stimulants: promote wakefulness and energy.

    • Depressants: slow nervous system activity.

    • Opioids: reduce pain.

    • Hallucinogens: alter perception.

    • Psychotherapeutics: treat mental disorders (antipsychotics, antidepressants, anxiolytics, analgesics).

  • By Chemical Structure or Origin: Opiates derived from opium poppy.

  • By Mechanism/Site of Action: Drugs classified by how they work in the body (e.g., antidepressants).

  • By Legal Classification: Drugs evaluated based on their potential for abuse.

Basic Pharmacology

Pharmacokinetics (PharmK)

  • Focus: How the body handles drugs:

    • Absorption: Movement from entry site to blood and action site.

    • Distribution: Storage and placement in body compartments.

    • Excretion: Removal of drugs from the body.

Pharmacodynamics (PharmD)

  • Focus: How drugs interact with the body:

    • Mechanism of action and drug effects.

Mechanisms of Drug Action

  • Drugs alter neurotransmission by changing:

    • Supply, release, reception, and termination of neurotransmitters.

    • Agonists: Facilitate neurotransmission.

    • Antagonists: Inhibit neurotransmission.

Key Players in Drug Action

  • Stimulants: Increase alertness and mood (e.g., cocaine, amphetamines).

  • Opiates: Reduce pain by attaching to endorphin receptors (natural: morphine, heroin; synthetic: methadone).

  • Hallucinogens: Alter perceptions (e.g., LSD).

  • Alcohol: Stimulant effects initially, then depressant effects; alters GABA and glutamate receptor activity.

Addiction and Substance Use Disorder

Definitions

  • Addiction: Compulsive substance use despite negative consequences.

  • Substance Use Disorder (SUD): Characterized by behaviors and physiological responses relating to substance abuse and dependence.

    • Criteria for SUD (DSM-V): Using larger amounts than intended, desire to cut down but unable, excessive time obtaining/recovering from substance use, cravings, neglecting activities, tolerance, and withdrawal symptoms.

Brain Mechanisms of Reward

  • Dopamine's Role: Key neurotransmitter in the brain's reward system; behaviors that release dopamine (e.g., sexual activities, gambling).

  • Positive Incentive Theory: Drug use motivated by the anticipation of positive effects.

Recovery from Substance Use Disorders

  • Recovery depends on the type of drug used, duration, and age of use. The brain can recover, but different substances lead to varying recovery trajectories.