drugs Flashcards
What is a ‘drug’?
A drug is any substance that alters the mind, affecting perception, consciousness, or behavior. Drugs such as heroin, cocaine, LSD, morphine, and nicotine are mind-altering. Drugs can be addictive, but so can other behaviors like gambling, sex, and social media. The effects of drugs can depend on the environmental and societal context.
How is addiction defined?
Addiction is defined by tolerance (needing more to achieve the same effect), withdrawal (physical symptoms when stopping), prioritization of use over health and social life, and inability to control use. Addiction can occur for both drugs and non-drugs, and the context can influence the level of addiction.
What is meant by ‘tolerance’ in addiction?
Tolerance refers to the need for increasing amounts of a substance to achieve the same high, due to the body’s adaptation. Tolerance isn’t universal and can vary depending on the substance and individual.
What is ‘withdrawal’ in the context of addiction?
Withdrawal refers to the physical and psychological symptoms experienced when a person stops using a substance they are dependent on. Some drugs do not cause physiological withdrawal, and addiction can occur even without withdrawal symptoms.
What are some common terms related to drug use?
Analgesic: Pain-relieving.
Stimulant: Increases physiological arousal.
Depressant: Lowers physiological arousal.
Endogenous: Originating from within the body.
Exogenous: Originating from outside the body.
What is the basic process of neurochemistry in drug use?
Neurons fire electrical action potentials that cause the release of neurotransmitters into the synaptic cleft. These neurotransmitters are then absorbed by receptors on the post-synaptic cell, and re-absorbed by the pre-synaptic cell in a process called reuptake.
What is the mesolimbic dopaminergic pathway?
The mesolimbic dopaminergic pathway is a key brain structure involved in reward and motivation. It connects the Ventral Tegmental Area (VTA) to the Ventral Striatum, including the Nucleus Accumbens (N.Acc), and is activated by dopamine.
How does dopamine relate to addiction?
The mesolimbic dopamine pathway is involved in the ‘reward’ system and in ‘incentive salience’—which refers to how rewards and their associated costs/benefits are processed. Drugs can increase dopamine release, reinforcing the behavior and contributing to addiction.
How do opiates/opioids affect the brain?
Opiates like morphine, heroin, and codeine activate μ-opioid receptors on VTA dopaminergic neurons, hijacking the brain’s reward system. They produce analgesia and euphoria but can lead to addiction by increasing dopamine release in the mesolimbic pathway.
What is opioid tolerance?
Opioid tolerance occurs when repeated use leads to reduced sensitivity to dopamine. This results in the need for larger doses to achieve the same effects due to the brain compensating for hyper-normal activation.
What are common withdrawal symptoms for opioids?
Opioid withdrawal can involve flu-like symptoms, shaking, aches, vomiting, anxiety, depression, insomnia, and intense cravings. The Locus Coeruleus, a brainstem nucleus, is key to these withdrawal symptoms.
How is opioid withdrawal treated?
Treatment often involves gradual reduction in opioid dosage, sometimes substituting with other opioids like methadone. Adrenaline antagonist drugs can also be used to help manage symptoms.
How do stimulants like cocaine and amphetamines work?
Cocaine blocks dopamine reuptake, leading to increased energy and focus. Amphetamines, including methamphetamine and methylphenidate, both block dopamine reuptake and increase dopamine release.
What is the difference between cocaine and methylphenidate (Ritalin)?
Both are stimulants, but cocaine is cleared from the system rapidly, causing people to take repeated doses, which may contribute to its addictive properties. Methylphenidate is used to treat ADHD and is considered safe when regulated.
How does nicotine affect the brain?
Nicotine activates cholinergic receptors on dopaminergic neurons in the VTA and Nucleus Accumbens, increasing dopamine release and enhancing attention and focus. Despite its addictive properties, nicotine’s hedonic effects are less intense than other drugs.
What are the effects of alcohol on the brain?
Alcohol enhances GABA activity, acting as a CNS depressant. It also increases dopamine release in the Nucleus Accumbens. Chronic use leads to tolerance and can cause extreme withdrawal symptoms, including Delirium Tremens.
What are SSRIs, and how do they work?
Selective Serotonin Reuptake Inhibitors (SSRIs) like Prozac and Sertraline block the reuptake of serotonin, affecting brain regions involved in mood, such as the amygdala, hippocampus, and prefrontal cortex.
What is the function of hallucinogens like LSD?
Hallucinogens inhibit serotonergic neurons and affect norepinephrine release from the locus coeruleus. They cause heightened perception and ‘ego-death’ by altering cognition and external stimuli responses.
How do operant conditioning principles apply to addiction?
Drugs can serve as unconditioned stimuli, inherently rewarding due to positive reinforcement (e.g., pleasure) or negative reinforcement (e.g., pain relief). Drug-associated cues can become conditioned stimuli, reinforcing the drug-seeking behavior.
What is the ‘Incentive Sensitization Theory’?
This theory posits that drug use sensitizes the ‘wanting’ system (mesolimbic dopamine pathway), making the desire for the drug stronger than the pleasure (liking) associated with it. Over time, users may ‘want’ the drug more, even though they no longer ‘like’ the effects.
