Drugs & Addiction Lecture Notes

Drugs & Addiction Study Notes

What is a Drug?

Definition of a Drug:
- A drug is defined as any substance that changes how your body or mind works.

What is Addiction?

Definition of Addiction:
- Addiction is characterized as a chronic (long-term) disease. - It is marked by an inability to stop using a substance even when it is harmful.
Causes of Addiction:
  - Changes in the brain due to alterations in dopamine levels.
  - Genetic predispositions to addiction.
  - Environmental factors influencing drug use and addiction.
Signs of Addiction:
  - Intense cravings for the substance.
  - Loss of control over usage.
  - Ignoring responsibilities due to drug use.
  - Withdrawal symptoms when not using the substance.

How Drugs Work

Mechanism of Action:
  - Drugs affect the brain by interfering with neurotransmitters (brain chemicals):
  - Agonists:
    - Act by mimicking natural chemicals and activating receptors.
    - Examples:
      - Heroin, marijuana   - Antagonists:
    - Act by blocking receptors.
    - Example:
      - Naloxone (Narcan)   - Reuptake Inhibitors:
    - These drugs keep neurotransmitters in the brain longer.
    - Examples:
      - Cocaine (affects dopamine), SSRIs (selective serotonin reuptake inhibitors affecting serotonin)   - Enzyme Inhibitors:
    - These stop the breakdown of neurotransmitters, prolonging their effects.

Drugs & the Brain

Impact on Reward System:
- Most drugs impact the brain's reward system by increasing dopamine levels leading to pleasure, which fosters repeated use.
Long-term Effects on the Brain:
- The brain compensates for repeated drug use by making less dopamine over time.
- There is a reduction in the number of dopamine receptors resulting in tolerance (where more of the drug is required to achieve the same effect).
Brain Areas Affected by Drugs:
  - Amygdala:
    - Responsible for stress and anxiety, particularly during withdrawal.   - Prefrontal Cortex:
    - Responsible for decision-making and impulse control.   - Thalamus:
    - Interprets sensory information about external stimuli.

Quick Bio Concept: Chemotaxis

Definition:
- Movement toward or away from chemicals.
Organisms Using Chemotaxis:
- Bacteria and immune cells utilize this process to locate food or avoid danger.

Types of Drugs

Stimulants:
  - Function: Increase energy, heart rate, and alertness.
  - Examples:
    - Caffeine, cocaine, meth.   - Medical Uses:
    - Used for ADHD and narcolepsy.
Depressants:
  - Function: Slow down bodily functions.
  - Effects: Cause relaxation and sleepiness.
  - Example:
    - Anti-anxiety medications.

Common Drugs

Cannabis:
  - Most widely used drug globally (~5% usage rate).
  - Main Chemicals:
    - THC (tetrahydrocannabinol): Psychoactive, responsible for the 'high'.
    - CBD (cannabidiol): Associated with medical benefits.
Caffeine:
- Classed as a stimulant and functions by blocking adenosine, thus promoting wakefulness.
Methamphetamine:
  - A very strong stimulant known for its high potential for addiction.
  - Forms:
    - Powder, pills, crystal (often referred to as 'ice').
MDMA (Ecstasy):
- Functions as both a stimulant and hallucinogen, increasing serotonin and dopamine levels leading to effects such as euphoria and energy.
Hallucinogens:
  - These substances alter perception and reality, primarily affecting serotonin levels.
  - Brain Effects:
    - Changes in thinking (Prefrontal cortex), loss of self perception (Default Mode Network), and emotional shifts (Hippocampus and amygdala).   - Examples:
    - LSD (lysergic acid diethylamide, commonly known as acid), mescaline.
Cocaine:
  - A stimulant derived from the coca plant, inducing energy and euphoria.
  - Dangerous Effects:
    - Can cause paranoia and rapid heart rate.
Opioids (Painkillers):
  - Natural:
    - Morphine, codeine.   - Semi-synthetic:
    - Heroin, oxycodone, hydrocodone.   - Synthetic:
    - Fentanyl, methadone.   - Effects of Opioids:
    - Provide pain relief but carry a high addiction risk and can lead to fatal respiratory depression.
Crack:
- A smokable form of cocaine, noted for a fast, intense high and high addictiveness.
Steroids:
- Synthetic substances mimicking testosterone, primarily used to promote muscle growth.
Rohypnol (Roofies):
- A powerful sedative that can cause memory loss and is often implicated in crime.
- Can be detected in urine for approximately 36 hours after ingestion.
Inhalants:
- Frequently the first drug attempted by teenagers due to easy accessibility, often termed 'gateway drugs'.

Key Takeaways

Drugs significantly alter brain chemistry and can lead to addiction, which is a brain disease rather than just a matter of choice.
Dopamine plays a crucial role in the addictive behaviors associated with various drugs.
Different classes of drugs influence the body in distinct ways based on their mechanisms of action.

Alcohol Study Guide

Basics:
- Alcohol contains approximately 7 calories per gram.
- It functions primarily as a depressant, slowing the nervous system's operations. - Alcohol also acts as a diuretic, increasing urination and potentially leading to dehydration. - It has significant effects on the brain and the nervous system.
Standard Drink Sizes:
  - Beer (approximately 5% alcohol by volume, ABV): 12 ounces.
  - Wine (11-15% ABV): 5 ounces.
  - Liquor (40% ABV / 80 proof): 1.5 ounces.
Key Terms:
- ABV (Alcohol by Volume): Measures the percentage of alcohol contained in a beverage.
- Proof: A measure of alcohol strength equal to twice the ABV value.
Alcohol Processing:
- The body metabolizes roughly 1 standard drink per hour. - Peak effects of alcohol are usually felt between 30 and 90 minutes after consumption. - Individuals experience impairment even after consuming just one drink.
Drinking & Driving:
  - Recommendations for waiting times:
    - After 1 drink (5 oz wine): wait approximately 1 hour.     - After 2 drinks (shot + beer): wait approximately 2 hours.   - Legal Blood Alcohol Concentration (BAC) Limit:
    - 0.08% is considered the legal limit for driving.
Terms Related to Driving Under the Influence:
  - BAC: Percentage of alcohol in the blood.
  - DUI: Driving Under the Influence.
  - DWI: Driving While Intoxicated.
Consequences of DUI:
  - Potential fines.
  - Suspension of driver's license.
  - Possible jail time.
  - Increased insurance premiums.

Breathalyzer in Car

Typical Costs:
- Installation costs range from $70 to $150. - Monthly fees can range from $50 to $120. - Maintenance and calibration costs approximately $20 to $30 every 1-3 months. - On average, it can amount to total costs in the hundreds to thousands of dollars depending on duration of requirement.

Binge Drinking

Criteria for Binge Drinking:
- For men: 5 or more drinks within about 2 hours.
- For women: 4 or more drinks within about 2 hours.

Factors Affecting Alcohol Absorption

Food Intake:
- Can slow down alcohol absorption into the bloodstream.
Body Composition:
- Higher fat composition can lead to a higher BAC.
Gender Differences:
- Generally, women have lower alcohol dehydrogenase (ADH) activity than men.
Medications:
- Various medications can influence alcohol absorption rates.
Carbonation:
- Carbonated alcoholic beverages tend to lead to faster absorption rates.
Speed of Drinking:
- Rapid consumption of alcohol increases absorption speed.

Alcohol Breakdown Enzyme

Alcohol Dehydrogenase (ADH):
- The enzyme responsible for metabolizing alcohol in the liver. - Note on Gender Differences: Women generally demonstrate a lower activity of ADH compared to men. - Certain populations, such as specific Asian groups, possess less effective aldehyde dehydrogenase (ALDH), which causes flushing following alcohol consumption.

Hangovers

Symptoms of Hangovers:
- Headache, nausea/vomiting, fatigue, dehydration (thirst, dry mouth), dizziness, sensitivity to light/sound, and trouble concentrating, accompanied by irritability.
Causes of Hangovers:
- Primary Cause: Acetaldehyde, a toxic byproduct produced when the body metabolizes alcohol.
- Secondary Causes: Congeners (chemical byproducts found commonly in darker alcoholic beverages) that can exacerbate hangover symptoms, alongside dehydration, poor sleep, and low blood sugar.

Congeners

Definition:
- Chemicals produced during fermentation.
- Typically found in larger quantities in darker alcohols (e.g., whiskey, red wine). - Congeners are noted for worsening the effects of hangovers.

Fetal Alcohol Syndrome (FAS)

Cause:
- Resulting from alcohol consumption during pregnancy.
Characteristics of FAS:
- Low birth weight, brain damage/developmental delays, learning disabilities, facial abnormalities (like a smooth philtrum, thin lips, and small eyes), and behavioral issues. - It is critical to emphasize that there is no safe trimester for alcohol consumption during pregnancy.

Responsibilities Regarding Drinking

Individuals should adhere to the following responsibilities when consuming alcohol:
  - Avoid drinking and driving.
  - Plan for safe transportation (e.g., designate a sober driver).
  - Be aware of personal consumption limits.
  - Protect oneself and others from the risks associated with alcohol consumption.

Conclusion

It is noteworthy that acetaldehyde is a primary toxic chemical produced during alcohol metabolism, and congeners contribute to hangover severity.
FAS is the second leading cause of mental retardation in America, emphasizing the seriousness of alcohol consumption during pregnancy.
Safe drinking practices should involve employing designated drivers or rideshare services (e.g., calling a Lyft) for transportation needs.
It is essential to recognize that 40% of vehicle fatalities are alcohol-related.
An upcoming lecture on tobacco will take place in two weeks, marking the finale of this series.