If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

Main content
Current time:0:00Total duration:3:19

Psychoactive drugs: Stimulants

Video transcript

as we talked about depressants which depressed neural activity and bodily functions and on the other hand we have stimulants which stimulate or intensify neural activity and bodily functions and these can range from your everyday stimulants like caffeine to more hardcore drugs like cocaine amphetamines methamphetamines and ecstasy and in between those extremes are nicotine which is found in cigarettes if you've ever tried to stay awake by drinking coffee or soda or something like that then you know that caffeine adds energy and can disrupt your sleep for several hours nicotine actually acts similarly it increases your heart rate and blood pressure and arouses the brain to a state of heightened alertness nicotine also suppresses your appetite which is one reason that people sometimes gain weight when they quit smoking without the nicotine their appetite returns so they eat more and a very high levels nicotine can actually cause muscles to relax and cause the release of certain neurotransmitters that may reduce stress and that's your body's natural response to try to counteract all that heightened alertness and tension caused by the nicotine both caffeine and nicotine are physiologically addictive meaning that your body grows accustomed to them and starts to experience negative reactions when you don't get enough for example you might know people who drink a lot of coffee every day or you might be one of those people and when if you don't get your coffee think about if you experience any headaches irritability difficulty concentrating even depression and that's withdrawal symptom from the caffeine and coffee and nicotine is even more addictive than that this is one reason it's so hard to quit smoking once the body gets used to nicotine its absence can lead to withdrawal symptoms like anxiety insomnia destructibility and irritability and cocaine is an even stronger stimulant it causes your brain to release so much dopamine serotonin and norepinephrine that it basically depletes your brain's supply and once the drug wears off you experience this intense crash and become very depressed regular cocaine users can experience emotional disturbances suspicions convulsions cardiac arrest or respiratory failure amphetamines and methamphetamines also trigger the release of dopamine and meth can cause a feeling of euphoria that can last up to eight hours but after that wears off people experience again intense irritability insomnia or even seizures and depression MF is highly addictive and people will literally just devote their lives to getting another fix long-term addicts might even lose the ability to maintain normal levels of dopamine as their brain tries to adjust to the intent ties