Biology of Substance Abuse Lecture 26 Biology of Substance Abuse

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

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

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

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

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

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

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

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

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

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

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