Pregabalin for anxiety in patients with schizophrenia - A randomized, double-blind placebo-controlled study

Anxiety is frequent in patients with schizophrenia and poses a major impact on patients perceived quality of life, daily functioning and risk of suicide. Pregabalin has shown effective in the treatment of generalized anxiety disorder and has been suggested for the treatment of anxiety in patients with schizophrenia. As evidence is sparse regarding treatment of anxiety in this patient group, we aimed to investigate the use of pregabalin for anxiety in patients with schizophrenia.

A randomized, double-blind placebo controlled study was used. Patients were randomized to either placebo or pregabalin (≤600mg/d) as add-on treatment. Primary analyses were intention-to-treat based with change in Hamilton Anxiety Scale after 4 and 8weeks of treatment as primary outcome. Secondary outcomes were change in psychopathology, quality-of-life, cognitive functioning and sleep. The study used centralized raters to increase accuracy and minimize baseline inflation.

A total of 54 patients were included with 46 completing the study. Pregabalin reduced the HAM-A₆ score significantly compared to placebo and with a medium effect size 0.72 (p=0.01). No significant between-group difference was found for the overall HAM-A₁₄. Most common side-effects were weight gain, dizziness, sedation and increased duration of sleep.

Although no effect was found on overall HAM-A₁₄, pregabalin might be effective in the treatment of psychic anxiety symptoms in patients with schizophrenia with a medium effect size.