Drug Dependence Flashcards
What are the four main classes of psychoactive drugs?
Depressants, stimulants, hallucinogens, opoids
Depressants
Psychoactive drugs that lower the body’s basic functions, decrease neural activity, decrease blood pressure, heart rate, and reaction times
Act on GABA receptors (an inhibitory neurotransmitter)
Three Classes of depressants
1. Alcohol- decreases inhibitions, lack of coordination, slurred speech
2. Barbituates- can treat anxiety/insomnia, not commonly prescribed due to negative side effects (reduced memory/concentration)
3. Benzodiazepines- commonly prescribed for anxiety (short or intermediate benzos) /insomnia (long term benzos), enhance brain’s sensitivity to the neurotransmitter GABA
Stimulants
Drugs that excite the CNS, increase heart rate, blood pressure, and alertness
examples include: caffeine, amphetamines, methamphetamines, MDMA (stimulant/hallucinogen), cocaine, nicotine, THC (also hallucinogen/depressant)
Hallucinogens
Created distorted perceptions/hallucinations, heightened sensations
examples: mescaline, peyote, PCP, LSD, psilocybin
Opiates (natural) /Opoids (synthetic)
Used to treat pain and anxiety. Have similar affects to depressants in that they decrease CNS function, decrease heart rate/blood pressure, cause relaxation, and induce sleep
They are different from depressants in that they act on endorphin receptors, rather than GABA receptors
Examples: morphine, oxycodone, heroin
How does nictotine work as a stimulant?
It is an acetylcholine agonist
How do cocaine, methamphetamines, and amphetamines act as stimulants?
They increase the release of dopamine from the brain
What is the relationship between drug dependence and homeostasis?
When you take a drug, your body tries to mitigate the effects of the drug
For example, if you take cocaine under the same conditions, your body may become conditioned to lower it heart rate in response to these conditions. If you don’t take the drug, heart rate may be too low. If you take the drug under different conditions, heart rate may be too high
Rank the following routes of drug entry fastest to slowest: oral, intravenous, inhalation
Intravenous, inhalation, oral
What is the reward pathway and how does it relate to drug addiction?
When the brain experiences happiness/reward through a drug it releases dopamine, which activates various parts of the brain. This causes the individual to seek out the drug in the future.
What part of the brain is dopamine released from?
The ventral tegmental area (VTA) in the midbrain
What parts of the brain have dopamine receptors and contribute to the reward pathway?
- Amygdala (controls emotions)
- Nucleus accumbens (controls motor function)
- Hippocampus (memory formation)
- Prefrontal cortex (attention)
What happens to serotonin levels when dopamine levels increase?
Serotonin decreases
Since serotonin is involved in satiation, increasing dopamine levels prevent feelings of contentedness
