Early access to clozapine in early intervention in psychosis: hope versus reality. A mixed method service analysis

Aim: Improving access to clozapine is a recognised priority nationally across Early Intervention in Psychosis Services (EIPS) in the UK. Treatment resistance (TR) may be identifiable from early episode psychosis and appears to be characterized by negative symptoms and younger age of onset. This mixed method cross sectional snapshot analysis of antipsychotic prescribing in an EIPS, explored clozapine eligibility (CE), and prioritisation of antipsychotic prescribing based on choice, selectivity and appropriateness. Method: We screened 150 service users and 79% (n=119) were retained after inclusion criteria were applied. We explored CE in all service users who were indicated clozapine based on the product licence (n=78), and whether there was association between CE and number of hospital admissions, antipsychotic trials, age at first episode and duration of untreated psychosis. Results: Following multidisciplinary clinical discussions, we found that 23 service users were CE; 8 were offered and declined clozapine. When compared to non-CE service users, significant factors associated with CE were history of 2 or more hospital admissions (Mann-Whitney U=269, p=0.008), more than 2 trials of 2 different antipsychotics (Mann-Whitney U=517, p=<0.01), and younger age first episode (independent-samples t-test, p=0.047). 47.5% of all service users had been started on olanzapine as their first antipsychotic, despite high risk of cardiometabolic syndrome. Conclusion: We propose that EIP services adopt a proactive approach in screening for TR, taking into account negative symptoms and young age at onset, prioritising service users with 2 or more hospital admissions and antipsychotic trials.