Public health and physician focused strategies to improve medication adherence in psychotic disorders

Abstract

Increasing the effectiveness of adherence interventions may have far greater impact on the health of the population than any improvement in specific medical treatments 1. However, literature on treatment adherence in mental health, as is evident in the scholarly review by Kane et al, is focused too narrowly on patient related and therapy factors. The structural barriers to adherence are generally overlooked. I argue that action is needed to address two important health system related factors: a) providing access to treatment for the estimated 40 million people suffering from schizophrenia living in low and middle income (LAMI) countries, and b) improving adherence through the implementation of evidence-based guidelines for treatment of schizophrenia. The treatment gap for schizophrenia is estimated to be 70-90% in LAMI countries 2, where the mean duration of untreated psychosis (DUP) in the first episode is 125.0 weeks 3. Endemic poverty in these countries seems to be associated with poor access to treatment and lack of adherence, except perhaps for most acute episode care. In a study that investigated the DUP and its relationship with gross domestic product purchasing power parity (GDPppp), it was shown that in LAMI countries an additional thousand dollars of per capita GDPppp was associated with a decline in mean DUP of ten weeks 3. Public health strategies which ensure free access to medication have been successfully implemented in other areas of medicine. In tuberculosis, for example, partial treatment adherence is more dangerous than no treatment at all, as partially treated cases result in drug resistance. This means that, once started, treatment must be completed. Therefore, tuberculosis control programmes worldwide have adopted a strategy called DOTS (directly observed treatment, short course). Two essential elements of this strategy are: a) regular uninterrupted supply of all essential anti-tuberculosis drugs backed by governments' commitment, and b) standardized treatment regimen administered under supervision. DOTS programmes have significantly reduced non-adherence to treatment in most developing countries, and are considered to be one of the most cost-effective health interventions 4. Such programmes have not only been implemented for high mortality disorders like tuberculosis and HIV infection, but also for non-communicable diseases such as diabetes mellitus. We believe that resources must be mobilized for a global fund to supply free medicines targeting the initial two years in the course of schizophrenia 3, 5. This would help to overcome non-adherence to treatment during this “critical period” in the course of illness, which is the strongest predictor of long-term outcome and disability. Such a treatment could be provided in DOTS-like programmes. The key elements of supervision and administration of medication by a close family member have already been adopted for schizophrenia. A proof-of-concept study showed that patients receiving treatment in the Supervised Treatment for Schizophrenia in Outpatients (STOPS) programme had significantly better adherence to medication compared to treatment as usual (p < 0.02) and showed significantly better outcomes in terms of symptoms and functioning at 1-year follow-up 6. Worsening of symptoms in psychotic disorders is often regarded as a consequence of poor treatment adherence, but there is robust evidence that premature treatment discontinuation is frequently due to poor control of symptoms 7. One study reported that treatment discontinuation due to inadequate symptom control was three times as likely as discontinuation due to medication intolerability. Ongoing depression and poor treatment response were found to be independent predictors of poor medication adherence in first episode psychosis patients 8. Current treatments have well-known limitations in controlling psychotic symptoms. However, evidence shows that the lack of adherence to treatment guidelines by treating physicians may be a major contributory factor to inadequate symptom control even in the best treatment centres. A multisite hospital study involving 508 people in Germany showed that, amongst patients with persistent psychotic symptoms, 73% received insufficient antipsychotic drug management and about 58% of those with depressive symptoms were not treated according to guidelines. Patients with more severe psychotic illness had a higher likelihood of not being treated according to guidelines 9. How much this poor adherence to treatment guidelines contributes to patients' poor compliance to treatment is not known at present. However, physicians may need to develop insight into their prescribing practices as much as the patients are expected to develop concordance with their advice. Pharmacological development in schizophrenia has been stagnant now for some decades. Optimizing treatment adherence can ensure that the available interventions are used in the most effective way. Taking medicine continuously for years with significant side effect burden in an illness that carries enormous stigma and disability is not easy. A public health approach is required, in which adherence is considered as a problem of the health system and the wider economic context, not just of the individual patient refusing to take medicine due to lack of insight.