Okay, welcome back. This begins module five of the course and what we're going to do in module five is we're going to talk about schizophrenia. Schizophrenia is a extremely important psychiatric phenotype. And rather than go through a lot of different psychiatric phenotypes, there's behavioral genetic research on any psychiatric phenotype you might imagine. What I want to do is go into one psychiatric phenotype in depth, so you get a, a fuller understanding, I hope, of the behavioral genetic approach or the psychiatric genetic approach to a, a phenotype, like schizophrenia. And then, next week actually, we'll do the same thing for a psychological phenotype, in that, in that case it will be intelligence. Really, schizophrenia is the prototypical psychiatric genetic phenotype. It's an extraordinarily important phenotype for psychiatry, for psychiatric genetics. It's important for a lot of reasons. One reason it's important is it carries a heavy burden associated with it. Individuals who suffer from schizophrenia have other difficulties in their lives. The, schizophrenia is one of the leading causes of disability according to the World Health Organization in the world. People with schizophrenia have reduced life stan, life span. In part because roughly 10% of people with schizophrenia, and that's 12 times the general population right, will commit suicide. Even on top of that though, they have a reduction in life expectancy of almost 15 years. People with schizophrenia have elevated rates of cardiovascular disease. There's an economic impact, both to the individual, for example, a majority of individuals with schizophrenia are unemployed, maybe 20% might be homeless in many Western countries. And in terms of healthcare, direct to healthcare costs, over a million dollars per individual. So, schizophrenia carries a heavy burden to society, to the individual with schizophrenia. It also carries a heavy burden to the family. Because schizophrenia is psychologically a very difficult disease to deal with. And that burden to the family was really, I think, compounded by what, for, throughout much of the 20th century we though schizophrenia was due to. Originally, schizophrenia, in fact, admittedly this was a while ago, but in fact, when I took, when I first learned about schizophrenia as an undergraduate, I learned about schizophrenia as being caused by schizophrenogenic parents. Actually, the term was schizophrenogenic mother. That parents cause this devastating illness in their children by communicating to them in, in bizarre ways. We now know that that's not the case and really it was primarily because of behavioral-genetic research in the latter half of the 20th century that really changed psychiatrists' view of what schizophrenia was due to. Now, in this first module I'm going to try to give you, I, I don't want to just jump into the genetics of schizophrenia. I, I'd really like us all to understand a little bit about what schizophrenia is. So, I'm going to talk about what it looks like clinically. I'm not a clinical psychologist, but I'll try to give you a sense for that. But I've also put a link on the course website site of a nice YouTube video of interviews with four patients with schizophrenia and I think if you could look at that before or after this lecture, and I think if you do, you'll get a pretty good sense for the types of things I'm going to be describing here. So, what is schizophrenia? First of all, where does the name come from and what does it mean? The original term for what we call schizophrenia today was Dementia Praecox, precocious dementia. And the term was actually introduced, or made popular, by a German psychiatrist named Emil Kraepelin. Kraepelin made a, a distinction between two major forms of psychotic illness. Disorders of mood, for example, bipolar disorder or disorders of thoughts, schizophrenia would be a disorder of thought. And he thought that this, schizophrenia was a form of precocious dementia because he thought it was a neuro degenerate, neurodegenerative disorder. That is, once you develop schizophrenia, you went on a down hill course, kind of like other neurological disorders like Huntington's Disease or ALS. In fact, and I'll get to this in a little bit, schizophrenia is not a neurodegenerative disorder. And so, the term schizophrenia was actually coined by a Swiss psychiatrist named Bleuler. Sometimes in the popular literature the term schizophrenia is confused with multiple personality disorder. Schizophrenia doesn't have anything to do with multiple personalities. Bleuler used the term schizophrenia to talk about a, a schism among various psychological or psychological or brain functions, in this case between emotional functions and cognitive functions. So what are the symptoms of schizophrenia? There's no pathognomonic symptom of schizophrenia, that is, there is no symptom that every schizophrenic has and that nobody without schizophrenia has. But there are close, clusters of symptoms that help to characterize a schizophrenic. The first cluster is illustrated here. Schizophrenics it's a thought disorder, dis, disorder. So schizophrenics have kind of illogical thinking process. And if you look at the films you'll see this. It comes out very well in some of the interview interviews of these patients. They suffer from delusions. Delusions are false beliefs. In the case of schizophrenics, their delusions are often paranoid delusions. So, they think that people are talking about them. Or they think that someone's broadcasting their thoughts over the radio wave. Or they think that somebody's controlling their thoughts. They put something in their brain like the CIA has control over their thoughts. Schizophrenics can hallucinate in any domain, in any modality. But the primary hallucina, hallucination is auditory. They hear voices. And the voices often feed into their paranoid delusions. The voices are saying nasty things about them. Many schizophrenics suffer from a movement disorder. And again, if you watch the YouTube video, you'll see that the, I think it's the fourth patient that they interview, engages in a movement over and over again, which is a, a typical movement disorder that you see in schizophrenia. These first cluster of symptoms are called the positive symptoms of schizophrenia. They are things that are not normally there, but are present in schizophrenia. The second cluster of symptoms are given here. Schizophrenics often suffer from inappropriate affect. And you again, you'll see this in the film. They'll have blunted affect. They'll have a hard time experiencing pleasure. They'll be demotivated or amotivated. And actually, maybe as a consequence of that, they'll experience a deterioration in their social behavior. They might have a hard time maintaining their hygiene or their health. We've already talked before about their difficulty with employment. Or with their relationships. The second cluster are called negative symptoms of schizophrenia. These are symptoms that are not normal, that are absent in schizophrenic that are normally there in, in, individuals who don't suffer from schizophrenia. The final clusters of symptoms are called cognitive symptoms and these primarily involve the inability to focus attention. To exert executive control over your cognitive functioning. And you'll see this again illustrated in the video, should you watch it. The clinical course of schizophrenia is illustrated here. It was once thought that schizophrenia had an abrupt onset in adulthood, but that prior to that, schizophrenics were really, in, individuals with schizophrenia were not different from the general population. We now know that if you go back early into the life, and, and this is difficult research to, to do, but people have done it. And looked at individuals who go on to develop schizophrenia, there's some, there's some reduction in their functioning, even early in life, in childhood. Those tend to be the negative symptoms of, of schizophrenia. At some point in their life, though, people who'll go on to develop schizophrenia will begin to deteriorate in in their functioning. This is called the Prodrome or Prodomo phase of schizophrenia. It can last a year or a couple of years. And you'll begin to see those positive symptoms of schizophrenia. A deterioration of functioning until there's an active phase. People with schizophrenia are not always sumper, suffering the symptoms of schizophrenia. They usually will get some form of treatment. Because that is such a devastating illness. And they will go into remission. Some people will function fairly well, maybe 20, 30% of schizophrenics after that. But 50, 60, 70% will cycle between periods of remission where they're functioning reasonably well and then they will relapse. There are treatments for the symptoms of schizophrenia, both pharmacological and essentially social work to help the schizophrenic deal with his, the individual with schizophrenia deal with his or her symptoms, but there's no cure for this devastating disorder. When does these onset occur? It occurs, this is a a graph of the first symptom, first positive symptom of schizophrenia, in German patients who developed schizophrenia. And what you see here is that the onset of this first symptom tends to occur in late adolescence or early adulthood. And you don't tend to get onsets of schizophrenia after that. It, it's not a disorder that you see onsets in middle age or later adulthood. It really is a disorder that onsets in early adulthood. The other thing about this graph, and I'm going to come back to in the next module, is the onset is a little bit earlier in men who develop schizophrenia than in women. It's a couple years earlier. And that's actually an important observation we'll come back to next time. So, it has this onset in early adulthood or late adolescence. It, it has this remitting course. How frequent does it occur? Well, how frequent it occurs the statistic that psychiatric geneticists usually use here is what's called the Lifetime Morbid Risk, and that's simply the probability that an individual will develop schizophrenia sometime during his or her lifetime. It's usually abbreviated LMR. So, what's the chance that a randomly selected individual will develop schizophrenia sometime during his or her life? It's about 1%. It might be a little bit less than that, probably not much greater than that. But a good rule of thumb is that about 1 out of 100 people in the world will develop this devastating disorder sometime in his or her lifetime. Next time we'll go into a little bit more about the epidemiology of schizophrenia. Thank you. [BLANK_AUDIO]
