1 / 24

Psychoactive Drugs

Discover the impact of psychoactive drugs on the brain, mood, and behavior. Learn about different types of drugs, their effects, and the risks involved. Explore psychological and physical dependence, tolerance, withdrawal, and cross dependence.

wbrito
Download Presentation

Psychoactive Drugs

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Psychoactive Drugs Drugs that affect the brain, changing mood or behavior. • 80-90% of adults in North America use some kind of drug on a daily basis. • The study of psychoactive drugs is called psychopharmacology.

  2. Depressants • – e.g. Barbituates; benzodiazepines (e.g. Valium); alcohol. • Reduced anxiety; feeling of well- being and lowered inhibitions; • slowed pulse & breathing; • lowered blood pressure; • Poor concentration/ confusion or fatigue; impaired coordination, memory or judgment; • respiratory depression or arrest.

  3. Stimulants • Stimulants– e.g. ephedra; • amphetamine; MDMA; • methylphenidate (Ritalin); cocaine • nicotine; caffeine. • Increased heart rate and blood pressure. • Increased metabolism; reduced appetite; • feelings of exhilaration, increased mental alertness; • irritability/ anxiousness.

  4. Opiates • Opiate and Morphine derivatives • – e.g. opium; morphine; codeine; thebaine. • heroin, oxycodone (OxyContin) • – Pain relief; euphoria; drowsiness; respiratory • depression & arrest; nausea; confusion; • sedation (unconsciousness, coma)

  5. Hallucinogens – e.g. LSD; mescaline; psilocybin. • – Altered states of perception & mood • nausea; increased body temperature; insomnia; weakness; tremors. • risk of chronic mental and perception disorders. Peyote: source of mescaline

  6. Cannabinoids • – e.g. hashish & marijuana • Euphoria; slowed thinking and reaction time; • confusion; impaired balance and coordination; • Impaired memory or learning • increased heart rate • anxiety; panic attacks

  7. Dependence Psychological Physical

  8. Psychological Dependence • Craving for the repeated or compulsive use of a drug because its effects are deemed pleasurable • Rewarded by effects • Positive reinforcement • Behavior shaped by seeking pleasure • Activating reward circuits in brain

  9. Physical Dependence • Dependence of the body tissues • Revealed by life threatening withdrawal symptoms • Degree of dependence unknown while drug use continues • Magnitude of withdrawal related to amount of previous drug use

  10. Adaptation of cells • Neurons alter function during drug use. • Lower activity • Greater activity • Function differently

  11. Withdrawal • Stop taking drug. • Brain rebounds. • If brain sedated by drug, withdrawing brain will be overexcited. • If brain excited by drug, withdrawing brain will be sedated.

  12. Sedative drug • Barbiturates or alcohol • Sedation while being used. • Excitability during withdrawal

  13. Stimulant drug • Cocaine or amphetamine • Brain overactive (manic) while drug being used. • Depression during withdrawal

  14. Cross Dependence • If physically dependent on one drug, • Dependence transfers to similar drugs. • Dependent on alcohol • Cross dependent on barbiturates. • Both sedatives

  15. Managed withdrawal • Cross dependence important for treatment. • Dependent on heroin (illegal drug) Withdraw person gradually using morphine (legal).

  16. Psychological Dependence • Craving for repeated use because of drug’s rewarding effect. • Learning. • Pleasure circuits. • Even psychological dependence has physical basis.

  17. Tolerance Level of adaptation

  18. Tolerance • Loss of responsiveness to something. • Noise; Traffic • Drugs • Takes more to get an effect. • Develop tolerance to any drug.

  19. Mechanisms for tolerance 1 • Pharmacodynamic • Action of drug on neurons • First time, neurons most responsive • With repeated use, tolerance develops.

  20. Mechanisms for tolerance 2 • Drug disposition • Breakdown of drug by liver. • Liver has enzymes to detoxify blood. • More drug use leads to increase in production of enzymes. • Increase drug use to stay ahead of enzymes.

  21. Initial Tolerance • We all begin live with certain level of tolerance. • Initial tolerance • Differs from person to person. • High initial tolerance is warning sign for addiction

  22. Developed Tolerance • Tolerance develops to all drugs taken repeatedly • Doses larger than prescribed Toxic dose Margin of safety Effective dose Initial dose

  23. Cross Tolerance • If tolerance develops to one substance in a class of drugs • Tolerance will transfer to other substances in that same class • Barbiturates and alcohol

  24. Reverse Tolerance • Liver enzymes detoxify blood • Break down drugs • Liver damaged • Tolerance lost • More affected by drugs

More Related