tag:blogger.com,1999:blog-4430111450575356526.post8423627872127712678..comments2024-03-22T22:09:09.407+00:00Comments on Imperfect Cognitions: Delusion in DSM-5: A Response to LisaKengo Miyazonohttp://www.blogger.com/profile/01643685718519136099noreply@blogger.comBlogger5125tag:blogger.com,1999:blog-4430111450575356526.post-61279378304804552272013-08-28T22:41:40.223+01:002013-08-28T22:41:40.223+01:00Thanks for the comment!
I agree that the definiti...Thanks for the comment!<br /><br />I agree that the definitions of delusion in DSM-5 are not very consistent with each other.<br /><br />Also, as you suggested, the lack of definition might not be a very serious problem for DSM-5. <br /><br />Still, it would be a good thing to think about various attempts (not just DSM) to define delusions. It might turn out that defining delusion is very difficult after all. Still, we will be able to learn something from knowing why delusions can't easily be defined. <br /><br />Here is an example. There is no accepted definition of "knowledge" in philosophy. But, knowing the reason why simple definitions of knowledge don't work helps us to understand what knowledge actually is. For instance, knowledge can't simply be defined as justified true belief because of so-called Gettier cases, the cases where justified true beliefs are achieved by luck. Thinking about these issues, I think, helps us to understand knowledge better, even though we don't have a good alternative definition of knowledge. <br /><br />The same thing might be true about the definition of delusion. The definitions of delusion in DSM are problematic. Still, we might be able to understand delusion better by looking at why these definitions are problematic.Kengo Miyazonohttps://www.blogger.com/profile/01643685718519136099noreply@blogger.comtag:blogger.com,1999:blog-4430111450575356526.post-70123124914606825432013-08-28T04:50:06.979+01:002013-08-28T04:50:06.979+01:00If you look at p. 87 of DSM-5 you'll see a sec...If you look at p. 87 of DSM-5 you'll see a section on Delusions. This is almost entirely a description of various kinds of delusion. Only a single sentence says anything relevant to defining delusion: "Delusions are fixed beliefs that are not amenable to change in the light of conflicting evidence".<br /><br />A completely different definition is offered on page 819 (in the Glossary of Technical Terms). Here we find that for something to count as a delusion, it has to be (a) a false belief based on incorrect differences about external reality and (c) held despite the existence of incontrovertible counter-evidence and (c) not held by other members of one's culture. As in DSM-IV.<br /><br />Since these definition are so contradictory (e.g one requires that delusional beliefs must be false and the other doesn't), there is no DSM-V definition of delusion.<br /><br />But does that matter? It would only matter if we were trying to make scientific or intellectual use of what DSM-V says about definitions; and DSM-V and DSM-IV are not fit for such purposes. So I don't see that readers of this blog should care about this at all<br />Anonymoushttps://www.blogger.com/profile/04238834651482248329noreply@blogger.comtag:blogger.com,1999:blog-4430111450575356526.post-60004935513857622402013-08-23T22:41:54.217+01:002013-08-23T22:41:54.217+01:00Sorry, I wanted to say that glossary excludes the ...Sorry, I wanted to say that glossary excludes the delusions that are TRUE.Kengo Miyazonohttps://www.blogger.com/profile/01643685718519136099noreply@blogger.comtag:blogger.com,1999:blog-4430111450575356526.post-90877786077172064302013-08-23T22:33:46.103+01:002013-08-23T22:33:46.103+01:00Hi Lisa,
Thanks for you comment!
I think you are...Hi Lisa,<br /><br />Thanks for you comment!<br /><br />I think you are right. It is certainly puzzling that there is no remarkable change in the definition in glossary. <br /><br />I also agree that the definition in glossary and the description of schizophrenia are not very consistent with each other. <br /><br />The main problem of the definition in glossary seems to be that it is too strong. It excludes the delusions that are false, the delusions that are not based on inference, the delusions that are not about external reality, etc. On the other hand, the description of schizophrenia in DSM-5 seems to be too weak. It includes many non-delusional beliefs. For instance, non-delusional racism beliefs are presumably "fixed" and "not amenable to change in light of conflict evidence". (In this sense, I agree that DSM-5 narrows the gap between delusions and non-delusional irrational beliefs. But, this narrowing makes the definition too weak.) So, it seems to me that the right definition of delusion is somewhere between these two... Kengo Miyazonohttps://www.blogger.com/profile/01643685718519136099noreply@blogger.comtag:blogger.com,1999:blog-4430111450575356526.post-6022331602027244342013-08-23T00:08:31.957+01:002013-08-23T00:08:31.957+01:00Hi Kengo and many thanks for this.
You're ri...Hi Kengo and many thanks for this. <br /><br />You're right that I should have compared definitions of delusions as they appear in the description of schizophrenia (those that appear in the glossary do not differ). <br /><br />The definitions provided in the schizophrenia section are different from one another in the way you discuss (no mention of delusions needing to be false or to be due to a misinterpretation of experience in DSM-5). The fact that the definition of delusions in the DSM-5 glossary doesn't reflect these changes is puzzling to me, especially as it wouldn't have taken long to make the two definitions of delusions in the DSM-5 more consistent with one another.<br /><br />There is a sense in which the gap between delusions and other irrational beliefs is narrowed if an irrational belief needs to satisfy fewer conditions to count as a delusion - but I agree this is kind of weak.Anonymousnoreply@blogger.com