Drugs Module 22

What are psychoactive drugs? chemical substances that alter perceptions, mood, or behavior altered state of consciousness 3 most common: caffeine alcohol nicotine

What is dependence? When does dependence become addiction? physiological and/or psychological need for a drug withdrawal follows if the drug is discontinued When does dependence become addiction? when the drug seriously disrupts a person’s ability to function in everyday life

Withdrawal discomfort & distress that follow when a person who is dependent on a drug discontinues use symptoms are usually the reverse of the drug’s effects example: heroin intended effect – euphoria, relaxation, slowed breathing withdrawal – depression, restlessness, rapid breathing

Tolerance reduced responsiveness to a drug user must increase dosage to achieve effects previously obtained by lower doses of the drug

Drugs and Neurotransmission How do psychoactive drugs work?

Neurotransmission process where neurons communicate with each other psychoactive drugs interfere with normal neurotransmission

3 ways drugs affect neurotransmission: Binding with receptors mimicking neurotransmitter’s effect example: morphine mimics endorphins Blocking receptor site preventing neurotransmitter’s binding example: Botulin poisoning (paralyzes) Blocking reuptake intensifies neurotransmitter’s effect example: cocaine blocks reuptake of dopamine (affects mood) increasing the amount in the synapses

Drug Classifications

Marijuana Description: Impact on Neurotransmission: derived from hemp plant lowers inhibitions & produces feelings of relaxation and mild euphoria Impact on Neurotransmission: Active ingredient: THC (delta-9-tetrahydrocannabinol) binds to cannabinoid receptor sites for neurotransmitter anandamide (pain relief, working memory, pleasure, eating, motivation) binds to receptor sites for dopamine (pleasure/euphoria) & triggers their release

Leaves, stems, resin, and flowers form the hemp plant Marijuana Physical & Psychological Impact: lowers inhibitions & produces feelings of relaxation and mild euphoria Health Concerns: 9% of users become addicted withdrawal symptoms: irritability, sleeplessness, decreased appetite, anxiety, & drug craving disrupts short-term memory (activity in hippocampus is reduced) interferes with normal functioning of the cerebellum (short-term) lung damage from smoke Leaves, stems, resin, and flowers form the hemp plant

Medical Marijuana (currently legal in 16 states & D.C.)

Hallucinogens Description: Impact on Neurotransmission: distort perceptions & cause sensory images in the absence of sensory input Impact on Neurotransmission: LSD (fungus that grows on grain)- stimulation of serotonin (mood, hunger, body temperature, sexual behavior, and muscle control) receptors on neurons Ecstasy (MDMA)– blocks the reuptake of serotonin (mood/pleasure) intensifying its effect; brain is depleted of its serotonin supply & depression is a common after-effect

Hallucinogens Physical & Psychological Impact: Health Concerns: LSD – visual hallucinations, detachment from reality, panic, sense of heightened understanding Ecstasy – hallucinations, rushes of exhilaration (stimulant), physical sensitivity, lowers inhibitions, euphoria, paranoia Health Concerns: LSD – tolerance develops rapidly, rapid heartbeat & high blood pressure, “bad trips” – paranoia, panic, delusions, dangerous behavior Ecstasy – damaged neurons w/ dumped serotonin, dehydration & heat exhaustion (club drug), increased body temp & blood pressure, nausea, blurred, vision, teeth/jaw clenching, depression/suicide

Stimulants Description: Impact on Neurotransmission: excite neural activity of CNS & speeds up body functions Impact on Neurotransmission: Caffeine – mimics adenosine (causes drowsiness) & blocks receptor sites Nicotine – mimics acetylcholine (learning, memory, muscle movement, energy) & binds to receptor sites; body must create more receptor sites; endorphin (pain killers) production Cocaine – blocks reuptake of dopamine (pleasure/emotion) Amphetamines (prescription stimulants, ADHD) - mimics adrenaline (forces release of stored adrenaline); increases dopamine (pleasure/ motivation/ attention) – also with Methamphetamines (over time destroys dopamine receptors – can’t feel pleasure, can regrow over years); release adrenaline Coca plant

Stimulants Physical & Psychological Impact: All – increase blood pressure & heart rate, faster respiration Caffeine – increases energy/alertness, reduces fine motor coordination Nicotine – arousal, relaxation, sense of well being Cocaine – euphoria, energy, increases body temperature Amphetamines – euphoria, suppress appetite, increase focus & attention Health Concerns: Caffeine – insomnia, nervousness, headaches, dizziness, lethal in massive doses (abnormal heart rhythms, seizures, breathing in vomit) Nicotine – death - heart/lung disease, stroke Cocaine - heart attacks, respiratory failure, strokes, seizures, abdominal pain, nausea; sudden death on first use (rare) Amphetamines – malnutrition, in high doses cardiovascular complications ( heart attack & stroke), amphetamine psychosis Methamphetamines – stroke, dementia, reduced motor speed, impaired cognitive abilities, increased sex drive, lower inhibitions

Caffeine & the Body

Depressants Description: Impact on Neurotransmission: reduce neural activity & slow body functioning Impact on Neurotransmission: Alcohol – binds to receptors for acetylcholine, serotonin, GABA (reduces neural activity), increases release of dopamine Sedatives (tranquilizers) Barbiturates & Benzodiazepines – binds to GABA receptors

Fetal Alcohol Syndrome Depressants Physical & Psychological Impact: Alcohol – relaxation, reduced tension, lowered inhibitions, impairs concentration, slows reflexes Sedatives – reduce anxiety or induce sleep Health Concerns: Alcohol – vomiting, breathing difficulties, unconsciousness, coma, impairs memory (suppresses REM sleep) damage to frontal lobes, kidney failure, vitamin B-1 deficiency, Fetal Alcohol Syndrome (alcohol use when pregnant) Sedatives: Barbiturates – lethal in overdose, impair memory & judgment Benzodiazepines – dependency Fetal Alcohol Syndrome

Opiates Description: Impact on Neurotransmission: depress neural activity & temporarily lessen pain and anxiety Impact on Neurotransmission: Morphine (derived from poppy plant) & Heroin (made from morphine) – mimic endorphins and binds to opioid receptors (pain, reward, critical life functions like breathing)

Opiates Physical & Psychological Impact: Health Concerns: Heroin & Morphine – rush of euphoria, relief from pain, clouded mental functioning Health Concerns: Heroin – overdose – stop breathing, use of needles (HIV/AIDS), liver or kidney failure Morphine – dependence leading to addiction, cessation of breathing, nausea, vomiting, constipation

Drug Quick Write Without using your notes: Choose one specific psychoactive drug from the five major drug categories we have studied. Explain how that drug affects neurotransmission and behaviors.

Drug Neurotransmission Review Impact on Neurotransmission Marijuana LSD & Ecstasy Caffeine Nicotine Cocaine Amphetamines & Methamphetamines Alcohol Barbiturates & Benzodiazepines Morphine & Heroin anandamide & dopamine serotonin adenosine acetylcholine dopamine adrenaline acetylcholine, serotonin, GABA GABA endorphins

Drug Classifications Marijuana Description Lowers inhibitions & produces feelings of relaxation & euphoria LSD Ecstasy Distorts perceptions & causes sensory images in the absence of sensory input Caffeine Nicotine Cocaine Amphetamines Meth Excites neural activity of the CNS and speeds up body functions Alcohol Sedatives (Barbiturates & Benzodiazepines) Reduces neural activity of the CNS & slows body functioning Morphine Heroin Depress neural activity & temporarily lessens pain & anxiety Marijuana Hallucinogen Stimulants Depressants Opiates