Combination clozapine and electroconvulsive therapy in a patient with schizophrenia and comorbid intellectual disability

To the Editor

Combination clozapine and electro-convulsive therapy (ECT) has demonstrated success for clozapine resistant patients (Havaki-Kontaxaki et al., 2006; Biedermann et al., 2011), however this combination has not been reported in the setting of schizophrenia and comorbid intellectual disability (ID).

Miss X is an 18 year-old woman with moderate ID who attends a special school. Her initial presentation was at age 16 with acute psychotic symptoms characterized by persecutory delusions, thought disorder and aggression. She had a complete response to risperidone, which was ceased within 18 months, however six months later, Miss X had a relapse characterised by thought disorder, auditory hallucinations, bizarre gesturing, dis-inhibition and aggressive behaviour. Treatment with risperidone and aripiprazole was unsuccessful and she required closed ward admission.

During the first four months of admission Miss X was unsuccessfully treated with quetiapine and zuclopenthixol. Consequently, the decision was made to commence clozapine. A partial response was observed with decreased thought disorder and less bizarre gesturing, however she continued to have auditory hallucinations, was disinhibited and displayed periods of physical aggression. Clozapine was then trialed in various combinations with amisulpride, aripiprazole, clomipramine and sodium valproate without any further improvement.

After an extended trial of clozapine for 7 months and doses up to 500mg daily, it was decided to commence ECT (bi-temporal) in combination with clozapine. Following eight treatments with ECT, significant improvement was observed with no evidence of ongoing auditory hallucinations or physical aggression. Miss X was then transferred to the open ward. However, 1-2 weeks following ECT cessation her aggressive behaviour returned. A second round of ECT with 12 treatments was performed, again resulting in improvement, but she once again relapsed 1-2 weeks after ECT cessation. For a third time, ECT was recommenced and coincided with behavioural improvement, leading to continuation ECT. With continuation ECT (currently at a total of more than 35 sessions), Miss X continues to show behavioural stability, is able to attend school, and has been discharged to supported community accommodation following a 16 month admission.

Of note in this case is the requirement for continuation ECT and according to a report from Hustig and Onilov (2009), 62.9% of patients receiving concomitant antipsychotics and ECT relapsed shortly following cessation of ECT. We suggest that clozapine and ECT combination treatment could be considered in patients with treatment resistant acute psychotic symptoms and comorbid ID, however maintenance ECT may be required.