Statistics
psychosis
REGRESSION, REGRESSIONS
Descriptive analyses and t tests were run in the software package SPSS statistics, version 24 [We analysed change per week in insight and the mPANSS in a latent growth curve model [After establishing level and change models for mPANSS and insight, levels of and changes in these variables were related to the three medication groups. These were each represented by two dummy variables: aripiprazole (D1 = 1, D2 = 0), olanzapine (D1 = 0, D2 = 1) and amisulpride (D1 = 0, D2 = 0), with the latter used as the reference drug due to its clean receptor profile. The model specified the predictive relationships between levels of and changes in mPANSS as outcomes on medications and levels of and changes in insight as endogenous outcomes on medications together with levels of and changes in mPANSS. In this way, levels of insight predicted by levels of mPANSS, changes in the first interval of insight by changes in the same interval of mPANSS, and a similar prediction in the second interval. Thus, this model has both direct relationships between medication and insight and indirect relationships via levels of and changes in mPANSS. Even if this is technically a mediation model, we see this model as a set of regressions. Instead of correlating medication and levels of and changes in mPANSS, which would give an ordinary regression model at the structural level, we specified a predictive direction between medications and the mPANSS intercept and slope factors. This direction is the only way these relationships could go. Even though antipsychotic medication is causally related to reduction in psychosis symptoms, this model does not assume that all included variables are causally related, as this would require biological, cognitive, behavioural, and contextual mechanism variables to be included. Our model contains only direct and indirect predictions. Accordingly, we use the term “effect” in the meaning of statistically effects, and not causal effects.We followed the protocol that was used in the primary trial [