Relationship between the clinical global impression of severity for schizoaffective disorder scale and established mood scales for mania and depression

BackgroundThis analysis explored the relationship between ratings on HAM-D-17 or YMRS and those on the depressive or manic subscale of CGI-S for schizoaffective disorder (CGI-S-SCA).MethodsThis post hoc analysis used the database (N=614) from two 6-week, randomized, placebo-controlled studies of paliperidone ER versus placebo in symptomatic subjects with schizoaffective disorder assessed using HAM-D-17, YMRS, and CGI-S-SCA scales. Parametric and nonparametric regression models explored the relationships between ratings on YMRS and HAM-D-17 and on depressive and manic domains of the CGI-S-SCA from baseline to the 6-week end point. A clinically meaningful improvement was defined as a change of 1 point in the CGI-S-SCA score. No adjustment was made for multiplicity.ResultsMultiple linear regression models suggested that a 1-point change in the depressive domain of CGI-S-SCA corresponded to an average 3.6-point (SE=0.2) change in HAM-D-17 score. Similarly, a 1-point change in the manic domain of CGI-S-SCA corresponded to an average 5.8-point (SE=0.2) change in YMRS score. Results were confirmed using local and cumulative logistic regression models in addition to equipercentile linking.LimitationsLack of subjects scoring over the complete range of possible scores may limit broad application of the analyses.ConclusionClinically meaningful score changes in depressive and manic domains of CGI-S-SCA corresponded to approximately 4- and 6-point score changes on HAM-D-17 and YMRS, respectively, in symptomatic subjects with schizoaffective disorder.