Treatment resistance to clozapine is estimated at 40–70% of the treated population. Several clozapine potentiation strategies have come into clinical practice although often without evidence-based support.

The aim of our work was to identify the potentiation strategies in ultra-resistant schizophrenia depending on the subtype of schizophrenia.

This is a prospective study conducted on patients with the diagnosis of schizophrenia, based on DSM-IV-TR criteria, and hospitalized in the psychiatric department of the university hospital in Mahdia, Tunisia. The study sample consisted of patients meeting the resistant schizophrenia criteria as defined by national institute for clinical excellence (NICE), and the prescription of clozapine for 6 to 8 weeks was shown without significant improvement.

we have collected 10 patients. The mean serum level of clozapine was 462.25 mg/L. The potentiation strategies were different depending on the subtype of schizophrenia. For the undifferentiated schizophrenia, we have chosen ECT sessions. For the disorganized schizophrenia, we opted for amisulpiride and aripiprazole. For the paranoid forms, we have chosen the association of risperidone and ECT. A psychometric improvement was noted in BPRS ranging from 34 to 40%.

Every potentiation strategy entails a cost, whether it is an additional monetary cost, adverse effects or greater stress to caregivers. The cost/benefit equation should be thoroughly evaluated and discussed before commencing a strategy.

The authors have not supplied their declaration of competing interest.