Effects of continuation versus discontinuation of antipsychotic treatment on white matter microstructure in first episode psychosis

Abstract

Background: Diffusion tensor imaging (DTI) studies have reported decreased white matter (WM) integrity in first-episode psychosis (FEP) patients. However, the impact of long-term exposure and discontinuation of antipsychotic medications on WM in FEP patients is unclear.

Methods: Fifty-four FEP patients three to six months in remission underwent DTI scanning at baseline and 31 patients were re-scanned after 12 months, during which patients either continued or discontinued antipsychotic medication. Voxel-wise between-group (continue/discontinue) comparisons of fractional anisotropy (FA) values were performed at baseline and follow-up. Additionally, linear mixed models were performed to assess the interaction between time (baseline/follow-up) and continuation versus discontinuation on FA values of WM tracts.

Results: Voxel-wise between group comparisons demonstrated no significant differences in FA at baseline or follow-up. However, longitudinal analyses indicated increased FA in the left (t = 2.53, p = 0.0181) and right (t = 2.38, p = 0.0251) corticospinal tract after antipsychotic discontinuation, although the results did not survive multiple comparisons correction. Further, a trend toward a relationship between the decrease in antipsychotic dosage and increased FA in the right cingulum (t = 2.029, p = 0.0597) was observed.

Conclusions: The current study provided tentative evidence that discontinuation of antipsychotics after achieving remission from FEP is associated with increased FA in the bilateral corticospinal tract. Future studies should investigate whether the changes in FA observed in this study reflect reversal of a pathological process, as this can provide important insight into the potential risks and/or benefits of antipsychotic maintenance treatment after FEP.