To say that schizophrenia and its treatment are complex and poorly understood is to take understatement to its limits. It is rather like saying the universe is quite big. The best we can say is that some people with a diagnosis of something we call schizophrenia will feel and function somewhat better if they take something we have decided to call an antipsychotic. Beyond that there is little certainty. We do not really understand, for example, why people stop taking antipsychotics in the numbers that they do. In this issue, Rune Kroken and fellow researchers report on their analysis of reasons for discontinuation of treatment in a naturalistic cohort. People prescribed clozapine or depot antipsychotics were least likely to stop treatment. Maybe this was because they were the most effective, we might guess: neither treatment is famed for its good tolerability.
Long-term treatment with antipsychotics is often accompanied by long-term prescription of anticholinergic drugs. What happens if these are withdrawn? Julie Eve Desmarais and coworkers examined the effects of slowly withdrawing long-term anticholinergics in 20 outpatients: 18 of these discontinued without a reoccurrence of movement disorder and this cohort showed a significant improvement in cognition.
Long-term anticholinergic treatment is just one of many non-evidence-based prescribing practices in schizophrenia. My colleague Anne Connolly and I examined two such practices (high-dose prescribing and polypharmacy) in a cross-section of patients across the UK. It seems prescribing high doses and two or more antipsychotics are not only closely linked but nor are they random acts. Both are associated with chronicity and illness severity, suggesting that non-evidence-based prescribing arises as a result of decreasing response to treatment.
A recent finding adding to our confusion about the nature of schizophrenia has been the potential for low vitamin D plasma concentrations to influence emergence and severity of the condition. Rabia Nazik Yüksel and coworkers from Turkey (not a country lacking in sunlight) examined vitamin D levels in remitted and acutely ill patients and found significantly lower levels in the acutely ill group. Cause and effect are still to be established but vitamin D supplementation has potential as a treatment for schizophrenia.
Three further papers complete this last issue of 2014. An Iranian study of 268 patients showed marked differences between olanzapine and risperidone in their effect on the cardiac QT interval. Olanzapine was more likely to shorten the QT interval than to lengthen it; risperidone showed only prolongation. From Turkey comes a case report and literature review of clozapine use during chemotherapy: a common clinical conundrum. Lastly, from India, Karthik and Prabhu describe a case of severe dystonia leading to mandibular dislocation caused initially by a single 2 mg dose of risperidone and latterly by a single 100 mg dose of amisulpride. A pertinent warning about the dangers of even the newer antipsychotic drugs.