Overview of psychoactive drugs | Processing the Environment | MCAT | Khan Academy

Overview of psychoactive drugs | Processing the Environment | MCAT | Khan Academy


– [Narrator] Psychoactive drugs are drugs that can
alter our consciousness. They can alter our perceptions,
influence our moods, calm us down, make us
feel more alert, etc. We classify psychoactive
drugs based on the actions and effects that they have on our bodies. When we do this we wind
up with four main groups : depressants, stimulants,
hallucinogens, and opiates. Drugs that are classified as depressants depress our central
nervous system function. They decrease the level of arousal or decrease the level of stimulation in certain areas of our brain. They decrease our heart
rate, lower blood pressure, slow our breathing. They can cause dizziness
and lack of coordination. Importantly they lower
our processing speed. This is important because it
can effect how we interpret and react to the things
that are going on around us. It will cause us to think more slowly and to act more slowly. There are a number of
different types of drugs that fall under this heading. One type is referred to as barbiturates. These are also sometimes
referred to as tranquilizers. These are drugs that are sometimes
prescribed to individuals to help them sleep or
to help them calm down. They are also sometimes
used in general anesthesia or as an anti-convulsant. The truth of the matter is that these drugs aren’t
actually prescribed very often because of the side
effects that they can have and because they have a
high addiction potential. They’ve mostly been replaced
by another type of depressant which are called benzodiazepems. These are prescribed for the same thing. They are prescribed to
treat insomnia, anxiety, and they are also used to treat seizures since they can depress
out of control activity. The last depressant I want
to point out is alcohol. It might surprise you that alcohol is
characterized as a depressant since it’s associated
with going out to bars and flirting and dancing with friends. Rather than producing a stimulating effect what is actually going on is that alcohol is lowering
their inhibitions. It’s decreasing their cognitive control. People who generally might
not dance in front of others, alcohol is stopping the thing that would generally stop them. Of course all of the other
symptoms of depressives are also present for alcohol. Things like lack of coordination and slurring of speech, etc. The next class of drugs that I want to talk about are stimulants. If depressants depress our central nervous system functioning, stimulants excite it. They stimulate our central nervous system. They increase our heart
rate and blood pressure and they increase our alertness. When people take them
they feel more awake. They feel more alert and energetic. They can also make people
really nervous and jittery, make them unable to sit still. You are probably very familiar
with one legal stimulant in particular and that is caffeine. This is the part of Coke and Pepsi and also coffee that
helps to keep us awake. You may have heard of
other stimulants as well. Things like amphetamines like Adderall, also methamphetamines and
MDMA or ecstasy or Mollie. Cocaine is also a
stimulant, as is nicotine. Nicotine is in fact a
stimulant and not a depressant. Even though it can cause relaxation it can also make people more alert. One thing that I want to
point out before I move on to the next class of drugs
is that while depressants and stimulants are functionally opposites they don’t necessarily
work on the same things on a neurochemical level. This is one of the reasons why
you can’t actually take one to counter the effects of the other. Drinking coffee after
you’ve had a lot of alcohol won’t actually sober you up. It will make you just a
more alert drunk person. The next class of drugs are hallucinogens. These are sometimes
referred to as psychedelics. These drugs cause individuals to experience distorted perceptions. This can include hallucinations, so seeing or hearing things that are different from
how things actually are. They can also cause heightened sensations. Sensations that feel real and might be based in reality but is actually different from what is really going on around them. To be clear these drugs aren’t
stimulants or depressants even though they can give
people a lot of energy or sometimes calm them down a lot. Instead these drugs are really classified by the perceptual changes
that they bring about. That can include a ton of different things in addition to hallucinations. In can also include emotional responses, feelings of connectiveness
but also intense mood swings. Moods that change very rapidly. This brings up a really interesting point about hallucinogens which is
that the exact experiences felt by the individual can
be different depending on the individual personalities or where they are or who they are with. This class of drugs
includes things like LSD which is sometimes referred to as acid, psilosiban which is an active
ingredient in mushrooms, and also things like peyote and PCP. The last class of drugs I want
to talk about are opiates. Which are sometimes called opioids. These terms are actually
used interchangeably although there is one small distinction. The term opiates is
generally used to describe natural varieties while
opioids are used to discuss synthetic versions. Like depressants, opiates can depress central
nervous system functions. They can decrease heart
rate and blood pressure, they can cause relaxation
and induce sleep. Because of this they are sometimes lumped under
the heading of depressants. While there are actually
important distinctions between them. The main one is that they actually work on different mechanisms
on a neurochemical level. Opiates also have an added feature that also distinguishes
them from depressants. They are an analgesic. They reduce the perception of pain. Some opiates that you might have heard of include morphine and codeine and heroin. It includes other substances
like oxycodone and Vicodin. Here we are we have four classes of drugs depressants, stimulants,
hallucinogens, and opiates. It might seem nothing fits
neatly into one category or another but the fact of the matter is that this is not a perfect system. That is because we created
the system of categorization. Nature did not. Because of this not all drugs fit neatly
into one category or another. Before when we talked
about MDMA or ecstasy we placed it in the stimulant category. It also could just as easily belong in the hallucinogen category. Since it does cause distorted perception and heightened sensations. What about cannabis? Where does marijuana go? It can cause perceptual distortion so it could go under hallucinogens but it can also decrease
central nervous system function and cause relaxation
much like a depressant. Of course this is just one way to classify psychoactive drugs. We could also have sorted
them by legal status or how likely they are to be abused.

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19 thoughts on “Overview of psychoactive drugs | Processing the Environment | MCAT | Khan Academy

  1. this is the best video on this subject ever !!!

    thanks very much , surely the owner of this video is incredibly genius that made the subject so easy to understand & differentiate 😀

  2. So MANY R so IGNORANT,, clinical DEPRESSION is the real killer, when we blame drugs on people's problems all we do is COVER the killer's footprints, Depression kills 40,000 people per year in the US, and over a million worldwide, Depression stems from a chemical imbalance, and when it is in a SEVERE stage, the pain is unbearable, HOW did all of you get so dumb??!!! in many ways DRUGS battle the pain that DEPRESSIIOn wreaks on the victim's life!!!!! all of you BAD MOUTHING substances should be ashamed of yourself!!!!!!!!!!!!!!!!!!~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

  3. mother of god! what an amazing lesson…. taught me how stupid it is to categorizes drugs like that… classify them as they are felt, lets collectively agree with that….!

  4. Video sounds like it just stopped all of a sudden (no wrap-up or anything. You were still disclosing points). Is this video a Part 1 or something?

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