This post is part of a series of guest posts on GPS by the graduate students in my Psychopathology course during Fall 2014. As part of their work for the course, each student had to demonstrate mastery of the skill of “Educating the Public about Mental Health.” To that end, each student has to prepare two 1,000ish word posts on a particular class of mental disorders.
Schizophrenia and Other Psychotic Disorders: Changes from the DSM-IV to the DSM-5
by Alexandra Logan
Compared to certain other disorders, there weren’t too many drastic changes to schizophrenia and other psychotic disorders in the latest edition of the Diagnostic and Statistical Manual of Mental Disorders. In fact, one of the changes from the DSM-IV to the DSM-5 is that the word spectrum itself was added to the category, making it Schizophrenia Spectrum and Other Psychotic Disorders. This change isn’t too extreme and just adds more depth to the disorder of schizophrenia by implying that there are different degrees of schizophrenia itself.
In the DSM-IV there aren’t different degrees of schizophrenia but there are different types. These included; paranoid type, disorganized type, catatonic type, residual type and undifferentiated type. These subtypes were all eliminated out of the DSM-5. This is the primary change to the schizophrenia category between the two manuals. More often than not you hear of people being diagnosed with one of these subtypes rather than simply schizophrenia. The elimination of these subtypes is a major change in the DSM-5 and it may take people some time to recognize that they are no longer considered diagnosable subtypes. This was changed due to there being so much overlap though between all of the subtypes that individuals typically met criteria for more than just one subtype making a diagnosis difficult to distinguish. Therefore, one of the main reasons for this change is that the subtypes were not stable enough conditions. There is often overlap between them all and they did not provide significant clinical validity. Clinicians could not determine with validity which subtype prevailed over the others so eliminating the subtypes altogether helps get rid of this instability.
As mentioned above, the catatonia subtype was eliminated but catatonia itself was turned into a specifier for schizophrenia and many other disorders, including depressive and bipolar ones. By taking the catatonia subtype out the DSM-5, the manual now recognizes that catatonia happens among many other disorders but doesn’t necessarily mean that the individual is suffering from psychosis. Along with this change there are two new catatonic disorders; catatonic disorder due to another medical condition and other specified catatonic disorder. Catatonic disorder due to another medical condition acknowledges that catatonia can occur with several medical conditions and it is not just attributable to schizophrenia or other psychotic disorders. Whenever the underlying condition of catatonia is unknown a clinician will use the other specified catatonic disorder term. This signifies that the clinician cannot determine if the catatonia symptoms are attributed to depression, bipolar, psychotic or other medical conditions.
There were also a few changes in the symptom criteria for some of the disorders listed in the schizophrenia spectrum. Starting with schizophrenia itself, one of key changes was the requirement of bizarre delusions and/or hallucinations. This has been taken out of DSM-5 because of the vagueness in the definition of bizarre: there was not an operational definition that was acceptable enough to aid in validity of diagnosis. The term bizarre also caused cultural bias. In some cultures having delusions and/or hallucinations is not only welcomed but also praised. Therefore, in these cultures it is not bizarre to have these symptoms, which created cultural bias in the terminology of symptoms for schizophrenia. So, in the DSM-IV the criteria for schizophrenia had to include two of the five main symptoms. However, if the individual only displayed one of the five symptoms they could be diagnosed if the one symptom was bizarre. In the DSM-5, with the term bizarre taken out the individual must display two of the five symptoms and one of those symptoms must be delusions, hallucinations, or disorganized speech.
Another area that the term bizarre was taken out of in the DSM-5 was delusional disorder. This change was different because the requirement that delusions be non-bizarre was removed in the DSM-5. To accommodate this change a new ‘delusion bizarre type’ specifier was established. Another change that was made in the delusional disorders was that shared delusional disorder is no longer a separate disorder on it’s own like it was in the DSM-IV. The symptomology in shared delusional disorder is now just considered delusional disorder.
There is a minor change in schizoaffective disorder in the DSM-5. In the DSM-IV the criteria for schizoaffective disorder required that a mood episode be present for a long or a substantial period of the time. In the DSM-5 this was changed from just a substantial period of time to a majority of the time. The individual must now present a mood disorder for the majority of their illness. This change although small was made in order to increase the validity of diagnosis and improve the stability of the disorder.
As mentioned above the biggest change made to the schizophrenia section between the DSM-IV and the DSM-5 is the elimination of the subtypes. This change was made in order to increase validity and reliability in diagnosing since these subtypes were not stable enough on their own. The rest of the changes made were minor. For instance adding the word spectrum to the title making it schizophrenia spectrum and other psychotic disorders. The term bizarre when regarding delusions and hallucinations was taken out in the DSM-5 for schizophrenia due to the vagueness of the term bizarre. What constitutes a ‘bizarre’ delusion or hallucination could vary across not only cultures but also individuals themselves.
Delusional disorder no longer recognizes shared delusional disorder as a separate or distinct diagnosis. The last minor change was the length of time a mood episode must be present for a schizoaffective disorder diagnosis. The time requirement changed from a substantial period of time to a majority of the time. In comparison to other disorders, the changes from the DSM-IV to the DSM-5, for schizophrenia and other psychotic disorders are not all that significant. However, changes are changes and need to be recognized in the field of psychology in order to keep diagnoses valid and dependable to the best of our ability. Even though the same basic diagnoses are still available in the DSM-5, the changes are important to know and understand.