Schizophrenia: Severity of Symptoms Predicts Medication Response

MedicalResearch.com Interview with:
Toshiaki A. Furukawa, MD, PhD

Professor and Chair, Department of Health Promotion and Human Behavior
Professor, Department of Clinical Epidemiology
Kyoto University Graduate School of Medicine / School of Public Health,
Yoshida Konoe-cho, Sakyo-ku, Kyoto Japan

Medical Research: What is the background for this study? What are the main findings?

Dr. Furukawa: The efficacy of antidepressants in the treatment of depressive
disorders has recently been called into question as some studies
suggested they may have less efficacy for the milder spectrum of the
disorder. It is not known if the same would apply to antipsychotics,
which constitute the mainstay in the treatment of schizophrenia. We
found that, in patients with schizophrenia with acute treatment as
well as with predominant negative symptoms, the severer the baseline
severity, the greater the magnitude of the benefit from the active
treatment in comparison with placebo.

Medical Research: What should clinicians and patients take away from your report?

Dr. Furukawa: Clinicians and patients can expect benefits of antipsychotic drugs for
the full spectrum of patients that we are likely to treat for acute
schizophrenia and for highly symptomatic patients with predominant
negative symptoms. Towards the mildest end of the spectrum, clinicians
need to be aware that patients benefit less in terms of symptom
improvement but may experience full side-effects of antipsychotics.

Medical Research: What recommendations do you have for future research as a result of this study?

Dr. Furukawa: First, in conducting placebo-controlled trials of antipsychotics, our
results suggest that trials would be more likely to detect signals if
they concentrate on severer patients. The current practice of setting
this threshold to 75 on PANSS may be justifiable in order to strike a
good balance between patient recruitment and signal detection; if
there is less difficulty in patient recruitment, the threshold could
be higher.

Second, the question remains why we often, though not
always, observe an influence of baseline severity on symptom reduction
in depression and schizophrenia, or if we observe similar
relationships in anxiety, insomnia and other psychiatric disorders and
in treatment of general medical diseases as well. Further empirical
studies to shed light on the mechanisms involved and to inform the
clinical practice and research methods are needed.

Citation:

Furukawa TA, Levine SZ, Tanaka S, et al. Initial Severity of Schizophrenia and Efficacy of Antipsychotics: Participant-Level Meta-analysis of 6 Placebo-Controlled Studies. JAMA Psychiatry. Published online November 05, 2014. doi:10.1001/jamapsychiatry.2014.2127.