Antipsychotic augmentation with modafinil or armodafinil for negative symptoms of schizophrenia: systematic review and meta-analysis of randomized controlled trials

Abstract

We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) of modafinil or armodafinil (ar/mod) augmentation in schizophrenia. We searched PubMed, clinical trial registries, reference lists, and other sources for parallel group, placebo-controlled RCTs. Our primary outcome variable was the effect of ar/mod on negative symptom outcomes. Eight RCTs (pooled N = 372; median duration, 8 weeks) met our selection criteria. Ar/mod (200 mg/day) significantly attenuated negative symptom ratings (6 RCTs; N = 322; standardized mean difference [SMD], -0.26; 95% CI, -0.48 to -0.04). This finding remained similar in all but one sensitivity analysis - when the only RCT in acutely ill patients was excluded, the outcome was no longer statistically significant (SMD, -0.17; 95% CI, -0.51 to 0.06). The absolute advantage for ar/mod was small: just 0.27 points on the PANSS-N (6 RCTs). Ar/mod attenuated total psychopathology ratings (7 RCTs; N = 342; SMD, -0.23; 95% CI, -0.45 to -0.02) but did not influence positive symptom ratings (5 RCTs; N = 302; mean difference, -0.58; 95% CI, -1.71 to 0.55). Although data were limited, cognition, fatigue, daytime drowsiness, adverse events, and drop out rates did not differ significantly between ar/mod and placebo groups. Fixed and random effects models yielded similar results. There was no heterogeneity in all but one analysis. Publication bias could not be tested. We conclude that ar/mod (200 mg/day) is safe and well tolerated in the short-term treatment of schizophrenia. Ar/mod reduces negative symptoms with a small effect size; the absolute advantage is also small, and the advantage disappears when chronically ill patients or those with high negative symptom burden are treated. Ar/mod does not benefit or worsen other symptom dimensions in schizophrenia.

Keywords: Armodafinil; Augmentation; Modafinil; Negative symptoms; Positive symptoms; Schizophrenia.