Types of depression and bipolar disorder in the DSM5

- [Voiceover] Typically when we think about depression, we think about major depressive disorder. But it turns out that there are other kinds of depression as well. And I want to take a moment to discuss some of them and the ways you might be able to remember the differences between them. So here we have a graph. And we have mood on the y-axis and time on the x-axis. So at our zero point would be an average mood. And then down here we have depressed moods. And up here we have mania or extremely positive moods. And if we have an average person, that person will go through normal emotional cycling during their life. Maybe they get into the college of their choice and then they get a job and then they lose a job. But all of these moods are in response to appropriate environmental and situational triggers. And they are also all temporary in nature. So they fluctuate, but they do so within an average range. And they do so as the person interacts with the world around them. Individuals with major depressive disorder might cycle normally through moods a lot of the time. But they will also have periods of intense depression. And these are often unrelated to what is going on around them. And so that's what these dips represent. These dips represent serious depressive states. But we also have another disorder that's called persistent depressive disorder or PDD. And this is a chronic form of depression. And it used to be called dysthymia in earlier editions of the DSM. So instead of having their baseline here, someone with persistent depressive disorder might have their baseline a lot lower down. And so all of their moods will happen within this depressive space. And as you can tell from where I drew this, PDD symptoms may not be as severe as the most intense depressive episodes. But this is still a very serious disorder. And as you can probably imagine, these symptoms can still have serious negative impacts on day to day life. And just to be clear, the symptoms for major depressive disorder and persistent depressive disorder are the same. But instead of lasting two or more weeks, like major depressive disorder, for PDD the symptoms must last consistently for two or more years. And I also want to add that sometimes people with PDD have additional bouts of even more intense depressive states. And when this happens, we generally say that the individual has double depression. We have seasonal affective disorder, which is sometimes shortened to S-A-D or SAD. And as you might have guessed, this is depression that is associated with different seasons. So it develops in the winter and fall and goes away or becomes less severe in the spring or summer. Another type of depression that doesn't fit super well on this graph is postpartum depression. And this is the depression that takes place in the first few weeks after a woman has given birth. And I want to point out right away that this is different from what is colloquially known as postpartum blues. It turns out that anywhere from 50 to 80% of women experience mild depression or mood swings after giving birth. But this generally only lasts a very short amount of time. And it's probably due to hormonal changes or may be related to the stress of giving birth and the intense emotions that can surround it. In contrast, actual postpartum depression is a depressive episode exactly like we would see with major depressive disorder. So it lasts a lot longer and is much more intense. But because it looks so much like major depressive disorder, some researchers have argued that this isn't actually a separate category at all, that postpartum depression is actually just major depressive disorder that just happens to occur after giving birth. And maybe it's just more noticeable to us because it is occurring at a time when we expect a woman to be overjoyed. Let's move on to talking about bipolar disorder. And this is actually two disorders, bipolar 1 and bipolar 2. In bipolar 1 an individual might cycle normally, but then they might swing between manic stages and depressive stages, so extreme highs and extreme lows. In bipolar 2 disorders the individual will cycle between depression and hypomania. And this is a less extreme version of mania. But we also have other disorders that are included in this group. And one is known as cyclothymic disorder or cyclothymia. And this disorder is characterized by frequent mood swings, so moving from a state of hypomania to a state of mild depression. And this disorder reminds me a lot of persistent depressive disorder, which, as I said before, used to be called dysthymia. And so I kind of think of cyclothymia as dysthymia for bipolar disorder. The mood changes are less severe, but they still exist, and they can have a strong negative influence on someone's life. And I want to discuss two more disoders that belong in this cluster. And one is known as other specified bipolar and related disorder, which is kind of a mouthful. But this diagnosis, which is new for the DSM-V, this diagnosis is for individuals who have some but not all of the symptoms of bipolar 2 disorder. So maybe they don't have quite enough of the symptoms or maybe their periods of mania or hypomania don't last long enough for it to meet the criteria for bipolar disorder. Another disorder that's new for the DSM-V that fits under this umbrella is premenstrual dysphoric disorder. And this describes mood changes, including intense mood swings, that can come about in the weeks before a woman has her period. And this could include a depressed mood or irritability or anxiety and can also include many of the symptoms that we see for major depressive disorder. But just as in the case with postpartum depression versus postpartum blues, I want you to note that this is different from what society has labeled PMS. This isn't someone just being kind of moody. PMDD can be pretty severe, and it can be really debilitating for the individuals who have it. And the last thing I want to mention is disruptive mood dysregulation disorder. And this one is also new for the DSM-V. If you're familiar with previous diagnostic categories in the DMS-IV, you might remember that there was a separate section for children. So there was a separate section for diagnosing children with disorders. But that section no longer exists in the DMS-V. And so all of those discussions about childhood disorders have been folded into conversations about adult disorders. And disruptive mood dysregulation disorder, it covers what used to be thought of as childhood bipolar disorder. So it can be used as a diagnosis for kids who are under 18 who show bipolar symptoms. So they might show persistent irritability or frequent episodes of out-of-control behavior. And once again, this goes beyond the temperamental behavior that we sometimes associate with the teenage or preteen years and even beyond the temper tantrums that we sometimes see in childhood. When we talk about out-of-control behavior here, we are talking about really intense outbursts. And they often require clinical attention. So we've talked about child bipolar disoder, but what about childhood depression? You might be wondering if it's the same or different as adult depression. And to answer that we really need to consider the fact that things like emotion regulation change and improve over our lifetime. And so young children, who aren't very skilled in emotional regulation, they might display depression differently from adults. So maybe they'll be irritable or angry instead of sad or maybe they'll have a lot of anxiety or they might have physical symptoms like persistent stomachaches and headaches. But even if it is expressed or experienced differently, childhood depression or the symptoms we might associate with it are a pretty good indicator of adult depression. So we haven't listed that here because the jury is kind of still out on it. But I think that that's a very positive thing because it reminds us that our understanding of these disorders is continuing to evolve. And even though our understanding of these disorders and our treatments of these disorders are pretty good right now, they'll be even more advanced and more sophisticated by the time the next version of the DSM is published.