MCAT Foundation 6 Lesson 7 Khan Academy: Drug dependence

4 types of psychoactive drugs

There are four main types of psychoactive drugs:

1. Stimulants: These drugs increase alertness, attention, and energy levels. Examples include cocaine, amphetamines, and caffeine.

2. Depressants: These drugs slow down brain activity and induce relaxation. Examples include alcohol, benzodiazepines, and opioids.

3. Hallucinogens: These drugs alter perception, mood, and consciousness. Examples include LSD, psilocybin mushrooms, and MDMA.

4. Opioids: These drugs relieve pain and produce feelings of euphoria. Examples include heroin, morphine, and prescription painkillers like oxycodone.

Effect of Depressant drugs on brain

They have a slowing effect on the central nervous system (CNS). They enhance the inhibitory neurotransmitter gamma-aminobutyric acid (GABA) in the brain, leading to decreased brain activity and relaxation.

Effect of Depressant drugs on body

The physiological effects of depressants include slowed heart rate, decreased blood pressure, and reduced respiration. They can also impair coordination, judgment, and memory. In higher doses or when combined with other substances, depressants can cause sedation, unconsciousness, and even respiratory depression, which can be life-threatening.

Long-term use of depressants can lead to tolerance, dependence, and addiction. Abruptly stopping their use can result in withdrawal symptoms, including anxiety, insomnia, tremors, and seizures. Prolonged and excessive use of depressants can also have detrimental effects on various organs, such as the liver and cardiovascular system.

Effect of opiates on the brain

They bind to opioid receptors in the brain, which are primarily located in areas involved in pain perception and reward. This binding leads to a decrease in pain sensation and an increase in dopamine release, resulting in feelings of euphoria and relaxation.

Effects of stimulant drugs on the brain

They increase the release and inhibit the reuptake of neurotransmitters like dopamine, norepinephrine, and serotonin. Do (Dopamine) Not (Norepinephrine) use Stimulants (Serotonin).

Effects of Hallucinogenic on the brain

These include LSD and psilocybin, which affect the brain by binding to serotonin receptors, particularly the 5-HT2A receptor.

Homeostatic response to drugs

When drugs are introduced into the body, they can disrupt the normal physiological processes. In response, the body may activate various mechanisms to restore balance and minimize the effects of the drugs. These mechanisms can include changes in drug metabolism, excretion, or receptor sensitivity. This can include certain physiological reactions and adaptations when the body knows the drug of interest will be ingested.

Routes of enter for drugs

The routes of entry for drugs into the body can include oral (through the mouth), inhalation (through the respiratory system), injection (intravenous, intramuscular (usually in the ass, think, steroid users), subcutaneous), transdermal (through the skin, and is kind of slow), rectal (through the rectum), and topical (applied to the skin or mucous membranes).

Reward pathway in the brain

The reward pathway in the brain is a neural circuit that plays a crucial role in motivation, pleasure, and reinforcement. It involves several key structures, including the ventral tegmental area (VTA), nucleus accumbens (NAc), prefrontal cortex (PFC), hippocampus, and amygdala.

Where is dopamine released

The ventral tegmental area (VTA)

What controls the bodies motor functions

The nucleus accumbens

What does the mesolimbic pathway consist of

The mesolimbic pathway consists of several key structures in the brain, including the ventral tegmental area (VTA), nucleus accumbens (NAc), and the prefrontal cortex (PFC).

What is the amygdala's function in the reward pathway

This a crucial role in the reward pathway by processing and regulating emotional responses, particularly those related to reward and pleasure. It helps in evaluating the emotional significance of stimuli and modulating the release of neurotransmitters like dopamine, which is associated with pleasure and reinforcement.

What happens to serotonin levels when dopamine goes up

It reduces

Drug Tolerance

Refers to the reduced response to a drug after repeated or prolonged use. It occurs when the body adapts to the presence of the drug and requires higher doses to achieve the same effect. Tolerance can develop to various drugs, including opioids, stimulants, and sedatives.

Physiological reason for drug tolerance

This is primarily caused by the downregulation of drug receptors in response to repeated exposure. This means that the body reduces the number or sensitivity of receptors, leading to a diminished response to the drug.

Drug withdrawal

This refers to the set of symptoms that occur when a person stops using a drug to which they have become physically or psychologically dependent. These symptoms can vary depending on the drug and may include physical discomfort, cravings, mood swings, anxiety, insomnia, and other symptoms.

Definition of drug intoxication

Refers to the state of being under the influence of a substance that impairs physical and mental functions. It occurs when the concentration of a drug in the body exceeds the normal therapeutic range, leading to altered perception, cognition, behavior, and physiological functions.

Substance use disorders

It is characterized by an inability to control or stop using the substance despite negative consequences.

Substance induced disorders

These are a group of mental health conditions that are caused by the use or withdrawal of substances such as drugs or alcohol. These disorders can include substance intoxication, substance withdrawal, mental disorders, and sleep disorders. They are characterized by a range of symptoms that can affect a person's mood, cognition, behavior, and physical well-being.

Drug detox

Refers to the process of removing toxic substances, such as drugs or alcohol, from the body. Detoxification can be done in various settings, including medical facilities or specialized detox centers, and may involve medical supervision, medications, and supportive care.

Cognitive Behaviour Therapy for drugs

Is a type of psychotherapy that can be used to treat substance abuse and addiction. It focuses on identifying and changing negative thought patterns and behaviors that contribute to drug use.

12 step programs

A type of support group that follows a structured approach to help individuals recover from addiction or other behavioral issues. They are based on the principles outlined in the original 12-step program developed by Alcoholics Anonymous (AA). These programs emphasize personal responsibility, surrender to a higher power, and support from peers who have gone through similar experiences. The steps involve admitting powerlessness over the addiction, seeking guidance from a higher power, making amends, and helping others in their recovery journey.

Motivational interviewing for drug addiction

This aims to enhance motivation and commitment to change by exploring and resolving ambivalence. It involves techniques such as open-ended questions, reflective listening, and affirmations to evoke and strengthen the person's own motivation for change.