The work group, however, stopped short of including it among core features because of its uncertain specificity to schizophrenia, lack of agreed-on measures that can be readily used in the real world, and absence of evidence that assessment is clinically indicated and applicable in this setting. In other words, more research is needed in this area, Dr. Gur said.
APS inclusion proves controversial
Dr. Ming T. Tsuang
One of the most controversial aspects of the DSM-5 is its inclusion of attenuated psychosis syndrome (APS), acknowledged Dr. Ming T. Tsuang of the University of California, San Diego.
About a third of patients with this constellation of symptoms develop a full-blown psychotic disorder, raising hopes that the APS diagnosis could help identify patients who will benefit from early intervention.
Some, however, have expressed concern that adding APS to the classification system might lead to inappropriate antipsychotic therapy.
"From our experience, that is not the case," Dr. Tsuang said. "Actually, the APS category may educate clinicians about the relative lack of utility of antipsychotic medication in this population. So we hope that if we have this category, inappropriate antipsychotic use among youth may be reduced."
"In the end, our task force decided not to put APS into the main body of the DSM-5, but rather into the appendix, because more research needs to be done to really test its validity and usefulness, particularly for clinicians," he concluded. "For the DSM-6, once we have more experience in this area and [more information from research], we may be able to put this condition in the main body. At that time, the name may change."
Closer to ICD but still distinct
The DSM-5 is likely to share much with the psychosis section of the forthcoming International Classification of Diseases, 11th revision (ICD-11), of the World Health Organization, expected out in 2015. Yet the two will still have their differences.
Dr. Wolfgang Gaebel
For example, both classification systems have deleted schizophrenia subtypes, replacing them with dimensional assessments in the case of DSM-5 and symptom specifiers in the case of ICD-11, noted Dr. Wolfgang Gaebel of the Heinrich Heine University Düsseldorf in Germany.
The two differ, though, with respect to diagnostic criteria, such as the requirement for functional impairment to make a diagnosis of schizophrenia and the inclusion of longitudinal criteria to make a diagnosis of schizoaffective disorder.
"There is some harmonization," he commented, while adding that there is still justification for having two classification systems, even if they are generally converging over time.
"Of course, on one hand, we would like to see one system which fits all. On the other hand, the two systems have different foci and always have," Dr. Gaebel said. "ICD is the system which has been used worldwide, mainly for administrative reasons. Some countries, in the clinical situation, use DSM, whereas many other countries use ICD, but when it comes to research, they use in addition DSM, also for publication because, of course, many papers you want to submit to Anglo-American journals that prefer the DSM. And I think the DSM has – this is my personal opinion – a more research-based focus.
"But I think the two systems profit from each other. I doubt for various, and I would say political, reasons that in the future we will have one system, although it would be very good to have it," he concluded.
Dr. Tandon, Dr. Malaspina, Dr. Gur, and Dr. Tsuang disclosed no relevant conflicts of interest. Dr. Gaebel disclosed that he is on the scientific advisory board of Lundbeck International Neuroscience Foundation and receives symposium support from Lilly Germany and Janssen Cilag Germany.