PARIS – A report that adjunctive minocycline was found safe and effective for treatment of schizophrenia must be considered one of the year’s highlights in the field of psychosis, Pascal Steullet, PhD, said at the annual congress of the European College of Neuropsychopharmacology.
The report came in the form of a meta-analysis conducted by investigators in China and Australia. This was the largest meta-analysis looking at the topic to date, and the only one to include a search of the Chinese language database, which provided three of the eight randomized, placebo-controlled clinical trials that were examined. Seven of the eight randomized trials were double-blind and deemed high quality by widely used criteria, including the Jadad scale and GRADE (Grading of Recommendations Assessment, Development and Evaluation) methodology, noted Dr. Steullet, a neuroscientist at the University of Lausanne (Switzerland).
The studies included 548 schizophrenia patients. The mean duration of the trials was 18.5 weeks, with the longest running 48 weeks. In five trials, minocycline or placebo was added to risperidone monotherapy.
The primary outcome was change in the PANSS (Positive and Negative Syndrome Scale) total psychopathology score, and the positive, negative, and general symptom subscale scores.
The biggest benefit was on PANSS negative symptoms. Minocycline brought significantly greater improvement in this domain than placebo, with a standard mean difference (SMD) of –0.69 and a P value of less than .00001 (Eur Psychopharmacol. 2017 Jan;27[1]:8-18).
“That’s quite a good effect size,” Dr. Steullet commented.
The benefit on PANSS positive symptoms, while statistically significant, was far less robust, with an SMD of –0.22 in favor of minocycline.
The PANSS total psychopathology score favored minocycline with an SMD of –0.64, which Dr. Steullet again deemed “a quite significant effect size.” The PANSS general symptom score also showed a significant benefit in favor of minocycline, with an SMD of –0.45.