Cognitive impairment in schizophrenia

[Music] hello I'm Dr Richard Keefe I'm a professor of Psychiatry at Duke University Medical Center in North Carolina in the United States um I'm going to talk to you today about cognitive impairment in schizophrenia which is the one of the most important aspects of the disorder um the the diagnosis of schizophrenia and often clinical psychiatrists who treat people with schizophrenia focus on the delusions and the hallucinations the so-called positive symptoms of the disorder and they often focus on these aspects of the illness because we do have drugs that can actually treat that aspect of the illness pretty well furthermore it's the as of the illness that often gets a lot of attention from the media we often hear about somebody who was driven by their delusions to do some a violent act or the the interesting nature in the media of people hearing voices so it's often the aspect of the illness that people think need treatment and in fact that aspect of the illness does need treatment but underlying the positive symptoms of the illness such as hallucinations and delusions are very profound cognitive impairments now what's interesting is that the diagnostic manuals that diagnose a schizophrenia both the the DSM the diagnostic and statistical manual that is used in the United States and elsewhere as well as the ICD uh 10th version which is used uh in Europe and elsewhere as well both of those diagnostic manuals really focus quite a bit on these positive symptoms of the illness but if we look here in uh the first sentence of the description of the illness in the American DSM fourth edition it says that the characteristics of schizophrenia involve a range of cognitive and emotional dysfunctions that include perception inferential thinking language and communication behavioral monitoring affect fluency and productivity of thought speech honic capacity valtion and drive and attention and you can see in red there there are four words that are highlighted that really are cognitive processes so although cognition is not something that get someone a diagnosis of schizophrenia it is very important very important aspect of the definition of the illness and the whole way that we diagnose schizophrenia in the next edition of the fifth edition of the diagnostic manual as well as the 11th edition of ICD um the international classification for diagnosis in those aspects we're going to actually be looking to to improve the amount to which cognition is considered to be a part of the diagnostic criteria so that's a real advance that has been based upon the most recent science in terms of understanding what really causes problems for people who have schizophrenia well one of the questions that people often have is how severe is the illness how severe are cognitive impairments in people with schizophrenia and you see here a profile of the cognitive impairment uh that's found in people with schizophrenia now uh different academic clinical researchers May disagree a little bit on what aspects of cognition are the most important for people with schizophrenia but largely people agree that there are seven um domains that are most impaired and I have them listed here as processing speed the extent to which someone can keep Pace paying attention a working memory which is keeping in information in mind for very brief periods of time verbal learning that is just learning verbal material being able to remember things like uh what somebody told you uh visual learning that is just remembering where you put things uh reasoning figuring things out and then social cognition which is things like understanding uh what somebody told you in the context of the the social situation or even things like remembering somebody's face or remembering somebody's name so those aspects of illness are all considered to be significantly impaired in people with schizophrenia just a little bit of a of a background in statistics here for those of you who might not be familiar with some of the the metrics that I'm going to be using uh while I talk to you today uh one is the zcore so a zcore is a great statistical tool where you can take any score on any test and you can put it in standard units so that all of the different tests have the exact same units and then you can compare them to one another so in the example I'm showing here today there are actually seven different uh aspects of cognition all with very different units some may have a score of 0 to 100 some may have a score of 1 to 10 but when you calculate the zcore you take a group of healthy people you give them the test and then you calculate the zcore based upon the performance in the healthy population so we see here that in the composite score and that's an average of all the different tests that people with schizophrenia are performing 2.5 Z scores below the healthy control population so what does that mean 2.5 zc scores that me that is equivalent to about the lowest 1% of the general population so to put that into equivalent for something like an IQ score that would be an IQ score of about 62 so that's at about the range of um a mental retardation um if we think of this in terms of something like an SAT score it would be an SAT score that probably would be in the 200s so these are obviously uh scores that are very very low in the overall population and by the way that's not to say that people SKR you have mental retardation but on these types of tests of cognition they perform um it that severely impaired and so it the main message I want to get across here is that the the presence of cognitive deficits in schizophrenic patients is is very very profound so when does cognitive impairment occur in people with schizophrenia well believe it or not we don't really know the answer to that we know that when people show up in the clinic at the onset of their illness we know that they're performing very very poorly on these tests we also know if we go back and we look at the records of people who develop schizophrenia or if we collect information on a lot of people some of whom eventually develop schizophrenia we know that prior to the onset of the illness that people who are going to develop schizophrenia perform about a half of a standard deviation below the healthy control mean and you can see I've put this under the premorbid uh Banner here on the far left of this of this uh chart so a half of a standard deviation that's very small that's only about seven or eight IQ type points but by the time somebody gets the full-blown illness there one and a half to two standard deviations below the mean and we don't know at what point the cognitive impairment occurs does it occur early on or does it occur at the onset of the illness the research on that is unclear we do know that throughout the course of illness that these cognitive deficits remain they may get a little bit better with successful treatment with antis psychotics but in general that two and two standard deviation difference between healthy people and people with schizophrenia persists throughout the course of the illness and that has some real consequences for it so I've listed some of the research here as just a few of the many many examples of the ways in which cognitive impairments affect people with schizophrenia first of all uh in the chart on the right this was a chart showing the difference between those patients who were able to work and those who are not as you can see the the people with schizophrenia who have the worst cognitive deficits that is those are in the gray bars they are actually less likely to be able to have a job and in fact in general people with schizophrenia struggle quite a bit to maintain a job and it's actually not because of their hallucinations or delusions so much because a lot of employers can tolerate those things if they come and go but one of the things that really presents a challenge is being able to keep Pace being able to remember what they're supposed to do paying attention at times when they need to pay attention those aspects of cognition are really a challenge for somebody to maintain their employment um some of the other aspects of functioning that are particularly important are things like being able to live independently um having a quality of life that's good as well as social relationships so a lot of social relationships depend upon each of the people in the relationship remembering things about one another paying attention to what each is saying thinking about what might be good for the other person all these aspects of social relationships are driven by cognitive domains that are severely impaired in people with schizophrenia so another question that people have is who's affected is it only some patients with schizophrenia or or uh is it everybody so one of the ways that we tried to address this because of course you can imagine an example where somebody may have uh be on the way to medical school or on the way to law school and then they have they develop schizophrenia and their cognition declines quite a bit so when that cognition declines you're taking somebody who's at the high end of the of the general population and if they have a decline they probably don't go all the way down to the lowest end of the healthy population but they probably have just as much just as significant a change so they may perform in the average range on a test but in fact that they're used to performing much better so we looked at this in our information that we have had available in our database and we looked at the relationship between cognitive impairment and mother's education turns out there's a very strong relationship because different families whether by environment or genetics have better cognitive performance and when we track the relationship here between mother's education on the on the x- axis at the bottom and then cognitive composite score on the y- AIS on the top you can see there's a pretty strong relationship but some people are performing above expectations some people are performing below expectations in the healthy population but when you put the folks with schizophrenia on this chart you see almost everybody is performing below expectations laid out by their mother's education but both genetically and environmentally so it suggested even those folks who are expected to do very very well they may they may perform average on cognitive tests but they're performing much worse than than would have been expected unfortunately there are not treatments that are available for cognitive impairment in schizophrenia there are some experimental but none have been approved by the regulatory bod such as the FDA in the United States we see here that some of the antis psychotics have a bit of an improvement on cognitive impairment halip paradol alanine copine sadone amisulpride as well as others improve patients who were in the first episode of psychosis probably because they reduced the symptoms and that Ena Ables people to perform better on neuropsychological tests but we find that later on in the illness even a switch of medication probably doesn't change cognition very much at all now this is a very uh busy slide filled with a lot of information and if you're interested in this I urge you to to look at this reference this is a a wonderful uh review of the literature by Dr till wees from The Institute of psychiatry in London and she amassed all of the studies that had used computerized cognitive remediation tools so these are computerized tests where somebody sits down and they practice over and over again various aspects of cognitive processing and in fact patients can get better and the amount of improvement is about 04 to 0.5 standard deviations so again you have a little bit of a bump up from being onto antis psychotics a little bit more of a bump up from these cognitive remediation tools what's very interesting and this is very recent research but some of these cognitive mediation effects appear to change the way the frontal cortex very important part of the brain way the way that part of the brain operates while people are engaged in cognitive tests and that amount of improvement appears to be long lasting because these patients who had that Improvement uh were functioning better six months later so some promising research um this from the University of South San Francisco Sophia vradov and her colleagues and then finally uh a number of the pharmaceutical companies are very interested in developing drugs that might improve cognition above and beyond cognitive mediation or the little benefit you get from antipsychotics this is an example very recently presented um at a research conference where a new medication appears to have a cognitive benefit so some of these new promising compounds are being studied by of pharmaceutical companies who are very eager to get a drug into the market that might really affect this incredibly devastating aspect of the illness so in summary cognitive impairments in patients with schizophrenia are profound they affect functioning tremendously currently there are no FDA approved treatments but there are a number of experimental treatments both behavioral and pharmacologic that appear to have some promise for targeting this incredibly important aspect of the disorder thank you very much [Music]

Channel: European College of Neuropsychopharmacology

Views: 100,961

Keywords: Richard Keefe, Schizophrenia

Id: Ba_f0C3kKjk

Length: 14min 37sec (877 seconds)

Published: Fri Oct 05 2012