Anxiety is a core symptom of schizophrenia that elicits significant subjective burden of disease and contributes to treatment resistance in schizophrenia. Anxious syndromes might be attributed to incompletely remitted delusions, the negative syndrome, depressive episodes, panic attacks, social phobia, avoidance after hospitalization, and down-tapering of benzodiazepine medication. Pregabalin, an antagonist at the α2δ subunit of voltage-gated Ca2+ channels, modulates several neurotransmitter systems and was found to alleviate anxiety in different mental disorders. In schizophrenia, this treatment option has not been evaluated before.
Here, we report a case series of 11 schizophrenic patients who had treatment-resistant anxiety and received augmentation with pregabalin. This observational analysis reveals that the strategy was able to significantly reduce scores on the Hamilton anxiety scale; furthermore, we observed improvements of psychotic positive and negative symptoms and mood as assessed by Positive and Negative Syndrome Scale, Scale for the Assessment of Negative Symptoms, and Calgary Depression Scale for Schizophrenia. After augmentation, both a complete discontinuation of concomitant benzodiazepine treatment as well as a dose reduction of antipsychotics could be achieved. We did not observe pharmacokinetic interactions or adverse events.
These observations suggest that treating anxious syndromes in schizophrenia with pregabalin can be effective and tolerable. Further investigations should differentiate schizophrenic subsyndromes of anxiety and evaluate benefits and risks of pregabalin in comparison to placebo and active competitors.