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Introduction to psychology - Depression and major depressive disorder

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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  • mr pink red style avatar for user Logan Dorr
    Is it possible a person with clinical depression doesn't want to be helped?
    (17 votes)
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    • duskpin ultimate style avatar for user SchaferGabi
      Yes, that is part of what makes depression so sad is that these people with depression think that their life is over all the time and don't want to continue living. Sometimes they even commit suicide, which shows that is really is a dangerous disease because self-preservation is human nature.
      (28 votes)
  • blobby green style avatar for user Jasmine
    This may sound obvious, but, could someone be suicidal but not depressed?
    (8 votes)
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    • duskpin ultimate style avatar for user Robin Austin
      It somewhat depends on how broadly you define the terms suicidal and depression. It is common for people to have fleeting thoughts of killing themselves without an actual desire to act on these thoughts. Sometimes there is simply a morbid fascination with the idea, but most people who entertain such thoughts are not actually being depressed and do not intend to actually hurt themselves.

      Also someone could be extremely unhappy and want to commit suicide, but still not meet official diagnostic criteria for clinical depression. For example, if someone suffers a tragedy and becomes suicidal immediately following they could not technically be diagnosed with depression because one of the criteria is that symptoms must persist for at least two weeks (they could be diagnosed with something else though, like Acute Stress Disorder). AND someone could feel suicidal, and simply not exhibit enough additional symptoms to meet criteria for a diagnosis of depression (at least five symptoms must be present for this diagnosis). Additionally, there are reasons besides depression that someone may want to take their own life, for example martyrdom.
      (7 votes)
  • leafers ultimate style avatar for user Kateri
    How do we know that a person will "Share" this feeling of depression? This point in the video sort of confused me.
    (6 votes)
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    • piceratops ultimate style avatar for user Ky
      I think the narrator meant that if you're around a depressed person then you could intake their negative feelings and become depressed as well. Humans are, whether we like it or not, social creatures. We tend to imitate others we are around, which is why parents often tell their kids to stick around friendly, optimistic (pretty much 'not bad') people.
      (10 votes)
  • leaf blue style avatar for user Challenge1student
    If you have trouble concentrating on schoolwork/reading/etc., would that be a reason/symptom of depression?
    (2 votes)
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    • piceratops seedling style avatar for user Polykinetics
      My major depression diagnoses was believed for many years to be ADHD/OCD, I was placed on ADHD meds for many years, but it was only masking my symptoms, not eliminating them. Come to find out, that many of the symptoms of major depression are very similar to those of ADHD. -Memory, cognition, attention span, the headaches. etc....
      The difference being that, per my own doctor, "ADHD is a nuisance, but depression can kill you" --Very serious medical condition. I'd say from experience....Talk openly and honestly to a doctor and pay attention to yourself very closely. You know when you are not feeling all right. Make notes if you need to, and then give that information over to your doctor so they can form a proper analysis of what you're experiencing.
      (8 votes)
  • duskpin sapling style avatar for user Guadalupe
    is there many jobs that involves psycology? (I wanna know since I want to study it and make a career out of it)
    (3 votes)
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    • starky ultimate style avatar for user Soph
      Oh, yes, there are a lot! If you want to diagnose patients you can get a Doctoral degree and become a clinical psychologist or a psychiatrist (who has an MD). You could also become a Neuropsychologist or Psychopharmacologist.

      Careers that don't involve having to get a Doctoral degree include working in schools as LPCs or School Psychologists. You can become a Psychiatric Nurse, a Marriage & Family therapist, a music therapist, or an art therapist. If you want to work with criminals, you can become a forensic psychologist.

      Or, you can involve yourself in the business part of psychology, such as in advertising, marketing, I/O psych, and other professions that are less mental health focused. There are a slew of paths you can take with a psychology degree! You will have to get at least a MA's or, even better, a Doctoral degree for most of these jobs.
      (5 votes)
  • female robot grace style avatar for user Sarah Hull
    How hard is it to overcome depression by yourself?
    (3 votes)
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    • female robot grace style avatar for user Supershirley
      It can be very hard. Especially since many people may not realize they have it. Even if they do realize that, they may not always have a clear grasp on what to do in situations where they have to deal with that issue. If they don't live in a positive environment, or if they don't have a positive peer or family system, that acts as an obstacle in the way in their search for self recovery.
      (3 votes)
  • duskpin ultimate style avatar for user Katta
    Is it completely ruled out that depression is caused by some kind of pathogen, like a virus or something?
    (2 votes)
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  • male robot hal style avatar for user Mohamed N. Ahmed
    At Would it not be more accurate if you call it "Biochemical factors" instead of "Biological factors"?
    (2 votes)
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    • female robot grace style avatar for user Supershirley
      Not necessarily, although it does make sense why you would ask that. Depending on what DNA you have, you may be more at risk, but if the family member that gave you the heightened risk didn't actually have those types of genes, it would make more sense to call it biological factors instead of biochemical.
      (3 votes)
  • blobby green style avatar for user Ghadamamdouh123
    At ..I wanna ask if the depression of a genetic cause like fewer receptors for serotonin why the symptoms of depression appear suddenly however, this patient has this number of receptors throughout life ??
    (2 votes)
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    • duskpin ultimate style avatar for user Robin Austin
      Actually nobody has a pre-set number of serotonin receptors -- these are actually produced in the brain and have a "lifespan" of a few days. The number of receptors that are produced can vary depending on both environmental and genetic factors (for example, dopamine receptors are reduced by chronic drug use, and will gradually increase again if drug use is stopped). So for someone with a genetic predisposition to low serotonin receptor production, depressive episodes will usually be triggered by a stressful life event. Sometimes though, the symptoms do NOT appear suddenly. Some people with this genetic predisposition have low grade symptoms (sometimes referred to as dysthymia) almost constantly, like it's a part of their personality.
      (2 votes)
  • starky seedling style avatar for user znoorsh
    This might be an obvious question but: Is it possible for someone to get over depression by themselves, or is professional help always required?
    (2 votes)
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    • old spice man green style avatar for user ColemanJohn25
      it's possible, but a person is more likely to get over their depressed symptoms with professional help, however some people refuse to seek help and this can lead them to find ways to deal with their depression in harmful ways such as self-mutilation or self-medication with drugs or alcohol, in all cases this leads to more increased depressed symptoms and leads to addiction. All in all a person is better off seeing a mental health professional
      (2 votes)

Video transcript

- [Voicover] Major Depressive Disorder, which is sometimes just referred to as depression, is characterized by prolonged helplessness and discouragement about the future. Individuals with this disorder have low self-esteem and very powerful feelings of worthlessness. They also lack the energy to do the things that they used to enjoy, much less the things that they have to do, or the things that they don't enjoy. They tend to feel socially isolated, and have trouble focusing on important tasks and have trouble making decisions. And this low mood tends to prevade all aspects of their life. There are a number of physical symptoms that also go along with depression. Lethargy, so feeling fatigued. Individuals with depression also tend to show fluctuations in weight. So either a lot of weight gain or a lot of weight loss. And they might also have trouble sleeping or they might sleep too much. And I think that these physical symptoms are often ignored, because in Western cultures, like in the U.S., we tend to think about depression in terms of moods or in terms of emotional states. But for individuals in some Eastern cultures, especially cultures where it might be seen as inappropriate to delve into or talk about feelings and emotions, people in these cultures tend to think about depression and experience depression in terms of these bodily symptoms, and so it's really important that these aren't discounted. Depression or depressive symptoms are the number one reason people seek out mental health services. And, because of this, some people have taken to calling it the common cold of psychological disorders. And I like that term for some reasons and I dislike it for others. What I like about it is that it captures how pervasive this disorder is. It is estimated that 13% of men and 22% of women, worldwide, could meet the criteria for depression at least once in their lives. And one study has shown that as high as 31% of college students might experience this disorder. And these are really high numbers. And so, in that way, I think that this term is appropriate. However, I think that the term common cold doesn't really capture the seriousness of this disorder. Because depression isn't just feeling down once in awhile. And it's not feeling sadness or grief at appropriate times, which is just a normal part of life. And I think that this term kind of minimizes that part of the disorder. Depression can be triggered by a life event, like a loss or a breakup, but it doesn't have to be. It also doesn't usually appear alone. It is actually really common for individuals with depression to have other disorders such as anxiety disorders. And I've been writing in this blue color to kind of signify depression, but I'm kind of getting bored with it now, so let me switch it up. So there are a number of factors that may be involved in depression and I'm going to split them up into three categories: biological factors, psychological factors and sociocultural or environmental factors. And let me, let me take a minute to get all of that down. All right. First of all, we know from family and twin studies that there's a genetic component to depression. And we also know from studies that use functional imaging that individuals with depression show a decreased activation in the prefrontal cortex. And this could be associated with the problems with decision making that people with depression tend to have. As well as their difficulties in generating actions. Researchers have also found lower levels of activity in the rewards circuitry in the brain. And this could help to explain why individuals with depression might not find enjoyment in the actions that they once found pleasurable. Depression has also been associated with certain neurotransmitters and neurotransmitter regulation. And I'll abbreviate that here by writing NT for neurotransmitter. Research has suggested that individuals with depression might have fewer receptors for serotonin and norepinephrine. And I think that all of this research is amazing. I think that it's really important. And it's also really compelling, in a way that research findings that include neuroscience typically are. But with that said, I really want to caution you against oversimplifying these biological factors. To give an example about why I'm saying this, I wanna talk about the relationship between a certain serotonin transporter gene and depression. And this gene is known as 5-HTTLPR, and I'll write that down. And a lot of findings have shown that this gene is involved in depression, but in actuality, it is only associated with depression if the individual with the gene is in a stressful environment. But the story doesn't actually end there, it's actually even more complicated. Because it turns out that if an individual with this genetic feature is placed in a warm and positive environment, they actually show a decreased risk for depression. And this is something that we don't totally understand yet, we're still trying to figure out why this might be the case. But importantly, I think that this really shows us how complicated biological factors can be. Let's move on to some psychological factors that might influence depression. One theory is based on the concept of learned helplessness. And this theory supposes that if an individual is exposed to aversive situations over and over again, without any power to change or control them, they might begin to feel powerless in a way that might lead to depression. So if someone is exposed to prolonged stress due to family life or bullying or some other cause that they don't have control over, their helplessness could spiral out of control and they might stop trying to change their situation because they perceive it to be completely helpless. And that's a behavioral theory or way of thinking about depression, but there are cognitive theories about it as well. And these theories tend to focus on thoughts or beliefs that, with repetition, could trigger depression. And while it's true that everyone has negative or self-destructive thoughts every once in awhile, generally we are able to step back from them, and we're able to realize that what we're thinking isn't completely logical. But sometimes people can get trapped in these thought patterns and they might put too much emphasis on negative thoughts and actions and experiences. And when they ruminate on these things, when they turn them over and over in their minds, it's possible that these cognitive distortions might lead to depression. Another cognitive theory about depression focuses on the concept of attribution or explanatory style. Now as we go about our daily lives, we naturally try to understand and explain the events that go on around us. And when we do this, we can either attribute the things we see to internal or external causes. So is it something that I did? Or is it something that happened because of something that is completely out of my control? Did I get a bad grade on a test because I didn't study? That would be an internal cause. Or did I get a bad grade because the teacher made a really unfair test? Which would be an external cause. Individuals with depression tend to attribute negative experiences to internal causes. So maybe they'll think that a friend didn't call or text back because they are unlikeable or unlovable and not because they were at the movies with their family and maybe their phone was off. In addition to this, they tend to see negative experiences as being stable, so they think that they'll continue to happen in the future. And they also tend to think that they're global, so they might assume that one friend not calling them back somehow signifies that none of their friends like them and together these things, these internal attributions, these stable attributions and global attributions, these things form a pessimistic attributional style and it might make certain individuals particularly vulnerable to depression. And there are many other psychological theories about depression. Things that have to do with coping style or self-esteem, but it can actually be hard to know whether these things cause depression or if they are the result of it. So does a pessimistic attributional style lead to depression or do people with depression tend to have a pessimistic attributional style? It isn't always clear. Environmental and sociocultural factors can also have a strong influence on depression. Having a friend or partner or roommate with depression can actually increase the likelihood that individuals around them will also develop depression. And although we don't know exactly why that is, some researchers suggest that it might have to do with co-rumination, where friends talk about problems and negative events. But instead of discussing how to solve them, they focus on the negative emotions and dwell on future problems and occurrences. And on some level, this is kind of normal. It is perfectly normal for close friends to take on some of the negative feelings of the other, like being sad when they lose someone who is close to them or being angry if they were dumped by their partner. This is just natural empathy. But the same empathy that allows us to comfort our friends when they're in distress, might also be the reason that depression seems to spread. We also know that individuals with a low socioeconomic status, especially those living in poverty, are more likely to develop depression, as are those who are struggling to keep a job or have just lost a job. And there are other environmental factors as well. Social isolation, child abuse, even prejudice have all been implicated in causing depression. And let's think about this in terms of prejudice. If someone grows up in a household that has negative feelings about homosexuality and if they grow up and begin to have same sex attractions, they've probably internalized the prejudice after years of hearing it and this could lead to depression. All right, so stepping back for a second, we said that we had biological factors, psychological factors and sociocultural and environmental factors. And when we put all of these things together, we get what is referred to as a biopsychosocial model of depression and this theory acknowledges that all of these factors play a role. So some people are genetically predisposed to the condition, but it only comes about if the situation is right or if we develop certain patterns of thinking.