Development and psychometric properties of a semi-structured clinical interview for psychosis sub-groups (SCIPS)

Background: Schizophrenia has long been considered to be remarkably heterogeneous, and there have been a number of attempts to identify sub-groups of this disorder which are more homogeneous. Nevertheless, most of these have not been used in either research or clinical practice to any great extent, because diagnoses by way of these strategies would be unstable over time and impractical. In such circumstances, the vulnerabilitystress model has led to the development of a new concept of sub-grouping schizophrenia into 4 sub-types – drug related, traumatic, anxiety, and stress sensitivity. This conceptualisation is quite promising, not only because it may provide stable and practical diagnoses, but also because the terminology used therein is useful when it comes to destigmatising those who are currently diagnosed with schizophrenia.<br/>Methodology: In order to adapt this concept for practical use, this project set out to develop a semi-structured interview for making diagnoses according to it. Thereafter, psychometric properties of the interview were examined. This assessment tool was then used to confirm the longitudinal stability of the diagnosis. In order to establish the construct validity of this classification system, it was examined if the anxiety and stress sensitivity sub-groups in this system were different in terms of their external validators. Three psychopathological variables – evaluative belief, fear of negative evaluation from others, and depression – were assessed in a cross-sectional study during this process of validation. Three other clinical variables – two for the duration of hospitalization and one for the risk of self harming – were also used in a retrospective cohort study for the evaluation of the predictive value of the differentiation.<br/>Results and conclusion: Both the English and Japanese versions of the semi-structured clinical interview for psychosis sub-groups (SCIPS) were developed to sub-group patients into 4 categories, and their reliability and concurrent validity were established. The 6 month stability of SCIPS diagnoses of the drug related, anxiety and stress sensitivity sub-types was also indicated through a longitudinal study. A preliminary analysis provided little evidence of construct validity. The risk of self harming was, however, suggested as being associated with a distinction between the anxiety and stress sensitivity categories when the SCIPS was applied to a broader range of psychosis, including schizophrenia and schizoaffective disorder.

Name dc:type.qualificationname

Ph.D.

Level dc:type.qualificationlevel

doctoral

Grantor dc:publisher.institution

University of Southampton

Year dc:date.issued

2009

Author dc:creator

• Kinoshita, Yoshihiro

Advisors dc:contributor.advisor

• Kingdon, D.
• Rathod, S.