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Risk factors for drug use and drug abuse

Visit us (http://www.khanacademy.org/science/healthcare-and-medicine) for health and medicine content or (http://www.khanacademy.org/test-prep/mcat) for MCAT related content. These videos do not provide medical advice and are for informational purposes only. The videos are not intended to be a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of a qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read or seen in any Khan Academy video. Created by Brooke Miller.

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Video transcript

- [Presenter] I think that talking about risk factors for drug abuse can be really difficult. And that's just because there are so many different factors that feed into it. And also, I don't want to put too much emphasis on any one cause. I don't want to demonize any one thing. So I want to say right off the bat, that there is no one thing that can lead to drug abuse or addiction. Instead, there are numerous factors that relate to each other in complicated ways. And I also want to mention that the presence of any, or even all of these risk factors does not actually guarantee that an individual will become addicted to any substance, or will even use at all. Alright, well with all of that said, now I am going to talk about some risk factors for substance abuse. So things that seem to correlate with substance abuse later in life. And we're going to talk about biological risk factors, psychological risk factors, and sociocultural and environmental risk factors. And let's start off with the biological factors. We know that if a child has a parent who abuses substances, they are more likely to abuse them as well. And this in combination with the fact that identical twins have more similar rates of addiction than fraternal twins, seems to imply that there could be a genetic component to addiction. This is also supported by the fact that adopted children tend to resemble their biological parents more than their adopted parents in term of addiction rates. But even if genetics are involved, even if someone can have a genetic predisposition to substance abuse, this does not guarantee that a person will develop a substance abuse problem. Instead, it might make them more vulnerable to having one. Another biological risk factor, has to do with the D2 receptor, which is a type of dopamine receptor in the reward circuitry of the brain. Some studies suggest that individuals with fewer D2 receptors, might have a higher risk of addiction than those with a typical amount of receptors. We know that many substances are associated with an increase in dopamine within the rewards circuits in the brain. And we also know that the body tries to counteract the effects of drugs through down regulation, so over time the body will take away dopamine receptors if too much dopamine is present. And this would stop an individual from feeling pleasurable experiences both when they take the drug, meaning that they'll have to take more to get the same high, but also in basically everything else in their life. And you can see how all of this would be particularly bad for individuals who had fewer D2 receptors to begin with. Having fewer receptors might also explain why individuals seek out drugs in the first place. Because it takes more stimulation for them to naturally get a reward signal. Another biological risk factor for addiction has to do with comorbidity. Meaning that individuals with certain psychiatric disorders, might be more likely to have substance abuse problems as well. One of these disorders is attention deficit hyperactivity disorder, ADHD. And this actually make a lot of sense to me, because individuals with ADHD tend to be impulsive. And as we will talk about later when we talk about psychological risk factors, impulsivity in general, seems to be a risk factor for addiction. Other disorders that can sometimes go hand in hand with addiction, are anxiety disorders and depression. And we're not entirely sure why this is the case, but some researchers have suggested that it might be because these individuals are trying to self medicate for their conditions. However, we should also remember that this is a correlation, and even though we might be tempted to conclude that mental disorders lead to substance abuse, that might not be the case. It could be that substance abuse leads to mental disorders. Or perhaps could trigger mental disorders in those who have a genetic predisposition. Or maybe both mental illness and substance abuse problems could be generated by a third factor. Maybe some genetic vulnerability for both. Either way, it's important to keep in mind when we discuss all of these risk factors, that correlation does not imply causation. Now let's move on to psychological risk factors. One thing that tends to get asked a lot, is if there is such as thing as an addictive personality. And the answer is, kind of. While there is no one single personality trait that causes a person to become addicted, researchers have identified a number of personality traits that seem to be present in many individuals with substance abuse problems. One of these is impulsivity, and I don't mean that in a fun, let's drop everything and go to the beach, kind of way. When we talk about impulsivity here, we mean an inability to control oneself. The inability to inhibit one's actions, even when faced with negative consequences. This is also sometimes referred to, as behavioral disinhibition. Another component is sensation seeking. The need to seek out high levels of external stimulation and new experiences. So a constant need for new, more thrilling things in life. Things like skydiving or extreme sports, or trying novel foods. Risk sensitivity also plays a role. So individuals who focus solely on the benefits of the experiences without thinking about the risks. Or maybe failing to see how the risks might apply to them. The last personality factor that I want to talk about is neuroticism, or being abnormally tense and anxious, and sensitive to stress. And these individuals might be at risk, because they might attempt to minimize their stress reactions through self medication. There are other psychological factors that can play a role, that aren't personality traits. For example, we also know that individuals who tend to score high on aggression tests, so individuals who have feelings of aggression and aggressive behaviors, who also tend to act out at school or at home, they also seem to be at a higher risk of developing addiction later in life. Age can also play an important role. People who begin using substances as adolescents, have a much great chance of having a substance abuse disorder later in life. Let's move on to environmental risk factors. And here especially, it is important to keep in mind, that the presence of any one of these factors, does not guarantee that a person is going to use or abuse substances. Instead, we are looking at a pattern of environmental factors that might make an individual more vulnerable to addiction. And one of the most important environmental factors seems to be the presence of stress in an individual's life. Both childhood stress, as well as current stress. And we know this both from examining the lives of those individuals who have substance abuse problems, as well as from a number of animal studies. Animals who are placed in stressful environments, tend to self administer more substances than animals who are not exposed to stressors. And when we talk about stressors, we mean a lot of different things. Some of them might be family related. Children in families with marital instability tend to have a higher risk, as are individuals who suffer abuse, whether that be physical or sexual or psychological. And before we talked about how evidence from family, twin, and adoption studies all seem to show that genes play a role in developing addiction, but it is also possible that there might be an added environmental effect as well in the form of modeling and imitation. So if a child watches a parent drink or use other substances as a coping mechanism, they might be more likely to model this behavior for themselves when they face stressors in adulthood. Lack of family involvement and family supervision also seems to increase the risk for substance abuse. As does not having a close family bond between an individual and their parents and their siblings. The friends an individual has can also play a role. If a friend group approves of substances and uses them, an individual is more likely to start. And this might be true for a number of reasons, one is that we make friends with people because of shared interests. And so we might hold things that our friends believe in high esteem. Another reason is social facilitation. Substances are often consumed in a group setting, and so they can serve to enhance social bonds. We have not mentioned it yet, but of course peer pressure can also play a role. Individuals might be pressured into using substances by their peers. Either directly, by them saying that the individual should use those substances, or indirectly, by giving the impression that it is, or will be an important part of peer bonding. The community an individual is in can also play a role. There is a higher concentration of substance abuse within low SES communities, and communities that are faced with poverty. Those who lack education and don't really have an employment history, seem to be at the greatest risk. But I want to point out something important, which is that while there might be more substance abuse within these low SES communities, there isn't necessarily more substance use. It could be that those in impoverished communities lack the safety net, things like education and strong support networks, and financial stability, that keep those in higher SES communities from moving from use to abuse. The availability of substances can also make a big difference. When substances are available, people are more likely to use. And the type of drug can also make a difference. Those with a fast rate of administration, so those that are injected or snorted or smoked, are more likely to be abused than those that are ingested orally, because they take effect faster. Because they produce a faster high, a faster reward. And this causes the brain to form a stronger association. Which might make it more likely that they will crave the drug again in the future. These substances also fade faster, which also makes users more likely to use again to continue the high. And you might think that all of these environmental factors are less important than some of the biological and psychological factors that we talked about before, but I want you to know that this just isn't the case. And so I want to take a minute to talk about a study that highlights how important they are You might be familiar with studies that show that a rat alone in a cage, with access to drugs will basically use continuously, sometimes neglecting food and water. But I want to point out that these rats are left alone in a cage with literally nothing else to do. And so they're in an environment without a lot of other options, except for using the substance. And to figure out what effect this might be having on the studies, some researchers built what was called the rat park. Which was a large cage filled with lots of engaging toys and fun things to play with, things like balls, and tunnels. And it also had the best rat food that they could get, and it had lots of rats all living together, all with access to the enriching food and activities. Basically it was rat paradise. And wouldn't you know it, even though the researchers made drugs available in rat park the same way that they were made available in experiments with a solitary rat in an unstimulating cage, the rats in rat park didn't abuse substances. And for those few rats who did use, it was in much smaller amounts. And this is absolutely incredible to me. And I still remember how shocked I was when I first learned it. And even though it's really hard to compare animal models to human models, I think it's important to consider what this might have to say about human substance abuse. So we've talked about biological risk factors, psychological risk factors, and environmental risk factors. But I want to note that even though I've discussed them separately, these three things are actually interconnected. Certain environmental factors might put an individual at a greater risk for drug abuse, but it is only when those things are combined with biological and psychological predispositions that they would start to take effect. Or saying that a different way, individuals with a biological predisposition and certain psychological traits, might only be at risk if they're placed within certain environmental situations.