Psychology Mod 22: Drugs Mrs. McVey Mod 22 page 408 Psychoactivity & Dependence Psychoactive drug is a chemical substance that alters perceptions, mood, or behavior Dependence: A state of physiological and/or psychological need to take more of a substance after continued use. Withdrawal follows if the drug is discontinued. Dependence becomes addiction when it disrupts a person’s ability to function in everyday life Psychoactivity & Dependence Withdrawal: the discomfort and distress that follow when a person who is dependent on a drug discontinues the use of that drug. Tolerance: Reduced responsiveness to a drug, prompting the user to increase dosage to achieve effects previously obtained by lower doses Drugs & Neurotransmission Remember CNS? Neurons? Neurotransmitter? Psychoactive drugs get into your synapses and affect neurotransmission in three ways: Binding with receptors or mimicking a neurotransmitter’s effect, which causes neurons to fire in the absence of normal stimulation Blocking receptor sites, preventing neurotransmitters from binding, and thereby not allowing neurotransmission to occur Blocking neurotransmitter reabsorption intensifying the neurotransmitter’s effect in the synapse Drugs & Neurotransmission Psychoactive drugs often bind BETTER and stay attached to receptors LONGER than normal neurotransmitters do, intensifying the drug’s impact on the body. Psychoactive drugs affect neurotransmission by binding with receptors, blocking neurotransmitter release, or blocking reabsorption See Figure 22.2 on page 411 Drug Classifications Five different categories Depressants Opiates Stimulants Hallucinogens Marijuana Drug Classifications Depressants: Drugs that reduce neural activity and slow body function **Alcohol: shuts down parts of your brain responsible for controlling inhibitions and making judgments Sedatives: drugs that depress the activity of the central nervous system, reducing anxiety but impairing memory and judgment (ex: Valium and Xanax) Barbiturates are prescribed as tranquilizers Drug Classifications Opiates: Opium and its derivatives, such as morphine and heroin, they depress neural activity, temporarily lessening pain and anxiety Morphine: strong sedative and pain-relieving drug derived from opium Endorphins: natural, opiatelike neurotransmitters linked to pain control and pleasure (exercise endorphins) Drug Classifications Stimulants: drugs that excite neural activity and speed up body functions Caffeine: stimulant found in coffee, chocolate, tea, and soft drinks (**caffeine withdrawal=moody, headaches) tolerance with regular use Nicotine: stimulant found in tobacco Cocaine: stimulant derived from leaves of coca pant Amphetamines: drugs stimulate neural activity, speeding up body functions, and associated energy and mood changes (speed or uppers) Drug Classifications Hallucinogens: Psychedelic (“mind-manifesting”) drugs such as LSD and ecstasy, that distort perceptions and evoke sensory images in the absence of sensory input LSD : powerful hallucinogen drug also known as acid Ecstasy: hallucinogen that produces lowered inhibitions, pleasant feelings, and greater acceptance of others. Even moderate use may result in permanent brain damage Drug Classifications Marijuana: leaves, stems, resin, and flowers from the hemp plant that, when smoked, lower inhibitions and produced feelings of relaxation and mild euphoria Medical Marijuana Has its own category because: its behavioral effects are similar to low doses of alcohol, but different than high doses because it doesn’t suppress breathing and isn’t lethal It produces very mild hallucinogenic experiences Chemical structure doesn’t resemble sedatives or hallucinogens Long-term costs of Marijuana Pot smoke is harder on your lungs than cigarette smoke Brain cell loss accelerates with large doses Memory is still impaired long after marijuana’s effect has worn off Marijuana seems to suppress the immune system, making it harder for your body to fight off disease and infection The structure of every hair on your body is detectably damaged with even a single marijuana experience, and no amount of conditioner can hide the damage Prevention Education is related to drug use—15% of US college dropouts smoke, as do 42% of high school dropouts Hope matters—Those who believe their lives are meaningless are more likely to do drugs Genetics play a role: there is a gene occurring more frequently among alcohol-dependent people than among others Peers count—if friends do not drink or smoke, teens are more likely not to do it.