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MCAT
Course: MCAT > Unit 11
Lesson 6: Psychological disorders- Psychological Disorders Questions
- What is obsessive compulsive disorder (OCD)?
- What is post traumatic stress disorder?
- Introduction to mental disorders
- Categories of mental disorders
- Schizophrenia
- Biological basis of schizophrenia
- Biological basis of depression
- Anxiety disorders and obsessive compulsive disorder
- Somatic symptom disorder and other disorders
- Personality disorders
- Sleep disorders
- Sleep wake disorders breathing related sleep disorders
- Reward pathway in the brain
- Drug dependence and homeostasis
- Tolerance and withdrawal
- Substance use disorders
- Biological basis of parkinson's disease
- Depression and major depressive disorder
- Depression and bipolar disorder
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Substance use disorders
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Want to join the conversation?
- Atit is stated the caffeine can not cause a substance use disorder. However, based on the criteria outlined under 'use' at 7:15caffeine does cause things line cravings, increased consumption, an inability to cut down, and can even cause physiological symptoms similar to a mild withdrawal when use is terminated. How then can caffeine not cause a substance use disorder when it is consistent with many of the criteria by which a substance use disorder is classified? 4:40(5 votes)
- I think the main difference is that caffeine doesn't interfere with daily obligations in work, school or home. Since it isn't impairing it is not a substance use disorder.(8 votes)
- From- 4:47criteria for substance use disorders are referred to. Are these based on the person's thoughts on the substance use or an external observer's thoughts on it? ("I feel my use of ..... is affecting my school vs My parents feel my use of ....is affecting my school ") 5:13(2 votes)
- This is a good question. It is more often based on external observers. The individual struggling with the use disorders doesn't always realize their tendencies are a problem. They may go through denial, like saying "I could quit any time."(6 votes)
- At, you graph out effect vs. dose. The graph implies that tolerance shows a decrease in effect that corresponds with an increase in dose, while you say shortly after that a decrease in effect at a consistent dose is a sign of tolerance developing. I'm pretty sure there's nothing wrong with what's said in the video, but the graph that is drawn could be misinterpreted. 6:30(3 votes)
- The x axis of the graph was # of doses/uses. So effect from 1 dose versus the effect from your 20th use of a substance.(2 votes)
Video transcript
- [Instructor] Let's consider drugs. I'm also going to call them substances. And as you know, there's a whole bunch of different drugs and
substances that people use. Some of the most common ones
include alcohol and tobacco, but also there's a range of other ones including cannabis, opioids,
that includes things like heroin, also things like stimulants, and that includes things like
cocaine and amphetamines, and a whole bunch of other things including hallucinogens, and that includes things like LSD, inhalants,
hypnotics, sedatives and other things. And let us not also forget one of the most commonly used substances which is caffeine commonly found in your
mug of coffee or tea. So when we look at drugs,
when we consider drugs, there's several things
that we have to also kind of look at. So, we have to consider what happens when drugs enter the body, and also what happens when they exit. These are two different processes. The first process, when the drug actually
goes into a human body, we can actually call this intoxication. And that's when the drug exerts its effect on somebody when it goes into their body. If it exits after a
period of prolonged use, we may experience something
called withdrawal. So what are we talking about
when we mention intoxication? We're talking about both the behavioral and psychological effects
of the drug on the person, and these can be very much drug specific. So, can we think of some
examples of intoxication? Well let me give you a couple of examples. When we're drunk, that's an example of intoxication with alcohol. Or when we describe
somebody as being high, that again, is a lay, colloquial way of describing where someone is intoxicated with another substance, which may be something like cocaine
or heroin, for example. So, what about when a substance
actually exits a person. Well, withdrawal happens
when we stop a substance, stop taking a substance
after having taken it for a prolonged period of time. And what happens there, is that
we get withdrawal symptoms, symptoms of stopping the drug. And these symptoms can make
us feel quite sick or ill, and in some cases, can be quite dangerous or potentially fatal,
depending on the drug. And when I say drug, I should
also say substance here. That's a more formal
way of referring to it. Both intoxication and
withdrawal, the effects really vary on the precise drug or substance that we are using. But let us also think about drugs or substances in a different way. Let us think about them on their effects on the human brain. Well know these substances
can actually result in a whole heap of other conditions, because they can result
in something called substance induced disorders. These are conditions that are actually caused by substances,
and these are conditions that could be substance
induced mood disorders, disorders of mood,
either experiencing moods that are too high, like mania, or moods that are too
low, like depression, disorders related to anxiety, sleep, sexual function. We may also get problems with
something called psychosis which is a loss of contact with reality, and that's where people can hear voices or see things, or become very paranoid. Now, when these drugs affect the brain, something completely
different may also happen. We can actually have the development of a substance use disorder. Not everybody that uses a substance develops a substance use disorder, which basically implies that
when they use this drug, the way that they're using
the substance or the drug is causing them a real
degree of impairment. It's really affecting the way
they function in their life. Whether that's at
school, work, or at home, their drug use is really impairing. Now let us talk about
substance use disorder a little further, because
when we talk about substance use disorder, the main issue that we are looking at is
that there is a problem here. There is a problem with
their substance use. And again, not everybody
that drinks alcohol or smokes cigarettes or uses a substance, not everybody has a
substance use disorder, but some people do. So let's have a closer look at this. How do we know they have
a substance use disorder? One of the ways that we can find out is by looking at their use. And there's really important factors that we need to consider here. Are they using increasingly large amounts? Are they experiencing increasing craving or strong desires to use? Are they spending more
and more of their time recovering from, or trying
to get the substances? Are they failing to try
and cut back or cut down? And also feeding into this use issue, are they experiencing problems related to their obligations
at work, at school, at home? If these things are appearing, that really does suggest
that maybe there is a problem and maybe they have a
substance use disorder. A second factor that we
look at, apart from use is the presence of something
we talked about earlier, and that was the presence of withdrawal. Now this is something that
happens after you stop using the drug after
prolonged or sustained use, and you can feel pretty sick or unwell with different symptoms depending on whatever drug you're using
after having stopped the drug. And this really also
suggests that physiologically you're dependent on the drug, your body's dependent on the drug. Withdrawal can be dangerous. For example, alcohol withdrawal. You can get seizures potentially, and die. Withdrawal symptoms are
specific to the substance. So again, the presence of withdrawal suggests that you have a problem. Finally, the last thing I want to mention, is the presence of
something called tolerance. What tolerance is, let
me graph it out for you. If this is the effect,
and this is the dose, the effect of the drug
decreases with subsequent doses. Your body adapts to, or builds a tolerance to the substance. So what people do, in order
to overcome this tolerance, is they tend to keep increasing the dose or the amount of the substance they use in order to achieve the
same level of intoxication. So, as we can see, the
way that people are using, and the problems that
they are encountering with the substance, the development of withdrawal symptoms and the
development of tolerance all suggest that we have a problem. Actually, just having a couple of these, such as craving or withdrawal or having using increasing amounts, not being able to cut down, is enough for us to be able to diagnose
a substance use disorder. And there's different severities of substance use disorder, from
mild, moderate, to severe. The one caveat I would
say, is that caffeine, of all the drugs that I've mentioned, with caffeine, we cannot develop a substance use disorder,
according to the common criteria. Now that may be an arbitrary thing, but I just want you to know that.