Drugs Flashcards
How do drugs interfere with neuronal signaling?
Drugs interfere with the way neurons send, receive, and process signals.
How do drugs impact the central nervous system (CNS) and autonomic functions?
Drugs can slow down or speed up the CNS and autonomic functions
True or False: Drugs only influence a select few neurotransmitters in the brain
False. Drugs influence several brain regions and our neurotransmitters
What role does the basal ganglia play in drug use?
● The basal ganglia are involved with motivation, pleasure, and the formation of habits and routines.
● Drugs over-activate this circuit producing the euphoria seen in the “high”.
● Repeated use reduces pleasure, though.
How does drug use affect the extended amygdala?
● The extended amygdala is involved with stressful feelings.
● Someone with a substance use disorder may use drugs to get relief from discomfort.
● This area becomes hypersensitive with increased drug use.
How does the prefrontal cortex influence drug-seeking behavior?
● The prefrontal cortex is involved with thinking, planning, solving problems, decision making, and self-control.
● People who use drugs will have problems with these functions.
● People may seek the drug compulsively.
What is dopamine responsible for and what drugs influence it?
● Function: Regulates mood and pleasure, and is involved with movement, reward, reinforcing behaviors, motivation, and attention.
● Drugs: Marijuana, heroin, opioids, stimulants, ecstasy, PCP
What is serotonin responsible for and what drugs influence it?
● Function: Responsible for stabilizing moods and regulating emotions
● Drugs: Ecstasy and hallucinogens
What is GABA responsible for and what drugs influence it
● Function: Acts as a natural tranquilizer, mitigates stress response, lowers anxiety, and slows down functions of the CNS
● Drugs: Benzodiazepines
What is norepinephrine responsible for and what drugs influence it?
● Function: Speeds up the CNS in the “flight-or-fight” response
● Drugs: Opioids and ecstasy
How do drugs work?
● Pleasure or euphoria is associated with the body’s neurotransmitters in parts of the basal ganglia
● When we take drugs, they cause an increase in these neurotransmitters
● The large surges of neurotransmitters “teach” the brain to seek drugs at the expense of other goals and activities
● External environmental cues trigger uncontrollable cravings; this “reflex” can last years even after someone is drug-free
How does repeated drug use lead to a loss of motivation?
● Drugs produce much more neurotransmitters than a natural situation.
● After repeated use, the brain produces fewer of its own transmitters in the reward circuit.
● Fewer neurotransmitters result in a loss of motivation. Individuals become lifeless, depressed, and unable to enjoy things that were previously pleasurable
What are the 7 main categories of drugs?
● Stimulants
● Depressants
● Opioids
● Psychedelics
● Cannabinoids
● Dissociatives
● Empathogens
How does cannabis (marijuana) affect the brain and what are the short and long-term effects?
● The psychoactive chemical in marijuana, THC, binds with cannabinoid receptors in the brain.
● Marijuana interferes with dopamine causing the euphoric “high”.
● Short-term effects: Impairs memory, motor skills, distorts time and perception, causes trouble thinking clearly and problem-solving.
● Long-term effects: Linked to the onset of psychosis and psychiatric disorders; can impair how the brain builds connections between areas, is associated with lower IQ, and reduction in hippocampal neurons and memory loss.
How do heroin and opioids affect the brain and what are the short and long-term effects?
● They bind to opioid receptors, triggering the release of dopamine.
● Can be abused from street drugs, but also from prescription opioids prescribed to relieve pain.
● Disrupt the natural production of norepinephrine and act as CNS depressants.
● Short-Term Effects: Blocks pain sensations, induces drowsiness, reduces body temperature, slows heart rate, blood pressure, and respiration functions.
● Long-Term Effects: Reductions in the brain’s white matter; poor responses to stress and poor decision-making; inability to regulate emotions; gray matter density is much lower in heroin users than healthy controls in many areas.
How does alcohol affect the brain and what are the short and long-term effects?
● Alcohol is a depressant drug, meaning that it slows down the messages traveling between the brain and body.
● Alcohol interferes with the white matter tracts controlling balance, memory, speech, and judgment.
● Affects GABA, serotonin, and dopamine.
● Short-Term Effects: Changes in mood and behavior, reductions in coordination and trouble walking, impaired thinking and judgment, blackouts, and amnesia.
● Long-Term Effects: Poor memory, changes in thinking and feeling, increased mental health issues, reductions in the number of neurons throughout the brain.
What is Wernicke’s-Korsakoff Syndrome?
● A progressive decline that starts with disorientation and confusion and is followed by memory loss.
● This syndrome is associated with cell loss in the thalamus and hypothalamus.
● Other changes include enlarged ventricles, smaller overall brain mass, and loss of volume in the frontal lobes, hippocampus, medial temporal regions, and the cerebellum.
How does cocaine affect the brain and what are the short and long-term effects?
● Stimulants speed up the messages traveling between the brain and body.
● Cocaine increases dopamine levels in brain circuits related to the control of movement and reward.
● The flood of dopamine reinforces drug-taking behaviors.
● Short-Term Effects: Extreme happiness and energy, increased mental alertness, hypersensitivity to sight, sound, and touch, irritability, and paranoia
● Long-Term Effects: Reduce blood flow in the brain due to damaged veins and arteries; people who abuse cocaine have double the rate of gray matter loss than those who did not; dysregulates the dopamine system.
How does LSD affect the brain and what are the short and long-term effects?
● A psychoactive substance that produces changes in perception, mood, and cognitive processes.
● “Bad trips” involve a disturbing hallucination which can lead to panic attacks and risky behaviors.
● Short-Term Effects: Alters a person’s thinking and mood/emotions; can cause visual hallucinations and distortions of time and space; confusion, and trouble concentrating.
● Long-Term Effects: Can trigger or worsen mental health problems, flashbacks, and psychosis; LSD is thought to influence neural plasticity and impair the serotonin system
How does ketamine affect the brain and what are the short and long-term effects?
● Makes people feel separated from their body or physical environment.
● Can also cause hallucinations or other changes in thoughts, emotions, and consciousness.
● Influences many neurotransmitters including glutamate, dopamine, serotonin, GABA, and acetylcholine.
● Short-Term Effects: Feelings of euphoria and relaxation, feeling detached from your body, slurred speech and blurry vision, hallucinations.
● Long-Term Effects: Mood and personality changes and depression, poor memory, thinking, and concentration; influences several brain regions including the hippocampus, prefrontal cortex, posterior cingulate cortex, and anterior cingulate cortex.
How does MDMA (ecstasy) affect the brain and what are the short and long-term effects?
● Increases feelings of empathy and benevolence towards others.
● Affects at least three neurotransmitters: dopamine, serotonin, and norepinephrine.
● Short-Term Effects: Feelings of euphoria, high energy and confidence, fast heartbeat and blood pressure, heightened senses, and hallucinations.
● Long-Term Effects: Can cause mood swings, dehydration, depression, memory, attention, and concentration problems; decreased brain activity in many regions; reduced glucose metabolism in several brain regions including those involved with executive functioning, memory, and emotional regulation
What are the main brain changes associated with drug use?
● Gray matter reductions: The cell bodies of neurons crucial for information processing decline.
● White matter damage: The nerve fibers that connect different brain regions are damaged.
● Reduced connectivity: The connections between neurons are impacted, leading to changes in neuronal density and neurotransmitter receptor expression.
● Reward pathway damage: The limbic reward pathway involved with pleasure is impacted.
How do drugs impact cognitive functions like memory, EFs, mood, emotion, and language?
● Memory and Learning: Deficits in memory consolidation and retrieval.
● Executive functions: Deficits in attention and focus, decision-making, impulse control, cognitive flexibility, inhibition, planning, and problem-solving.
● Mood and Emotion: Mood disturbances, depressive symptoms, anxiety; can exacerbate symptoms of underlying mood disorders.
● Language: The listed drug categories do not directly damage language function.
