1. Biology of Substance Abuse
Lecture 26
Biology of Substance Abuse

2. Drug Administration and Absorption
Ingestion
Injection
Subcutaneously (SC)
Intramuscularly (IM)
Intravenously (IV)
Inhalation
Absorption through mucous membranes

3. Drug Tolerance Definition Metabolic tolerance Functional tolerance
Cross tolerance
No unitary mechanism

4. Addicts Habitual drug users
Adverse effects on their health, social life
May be linked to psychological dependence

5. Tobacco
Nicotine
Acts on the nicotinic receptor (a type of acetylcholine receptor)
Increases blood pressure, heart rate, and release of epinephrine (adrenaline)
Addiction may have a genetic basis….?
Many side effects and withdrawal symptoms

6. Alcohol Most used and abused Affects general nervous system
Activates a specific type of GABA and glutamate receptor
Addiction has a major genetic component
Long term use can cause irreversible damage to the brain, liver, heart, and stomach

7. Marijuana Active ingredient is THC
Intensifies sensory experiences, increases appetite
Lack of energy and ambition
Many medical uses
Binds to cannabinoid receptors in the brain, but the exact mechanisms of action are not clear

8. Cocaine and Amphetamines
Crack cocaine
Extremely addictive, mild withdrawals
Blocks reuptake of NE and DA (catecholamines)
Effects are brief

9. Opiates Include morphine, heroin, codeine
Produces a pleasant state and decreases sensitivity to pain
Bad side effects
Attaches to endogenous receptors

10. Biopsychological Theories of drug addiction
Moral model
Disease model
Physical-dependence theory
Positive-incentive theory

11. Vulnerability to Drugs
Biological factors
Personal characteristics
Family situation
Social and community factors

12. Treatment for Drug Abusers
Drugs for detoxification
Agonists of drugs that produce addiction states
Antagonists to the addictive drug
Anti-craving medications
Medication that blocks drug metabolism