Schizophrenia News Roundup

Increased serotonin knowledge, a blood test for schizophrenia, and the prevalence of antipsychotic switching in schizophrenics.

Increased Knowledge of Serotonin Mechanism of Action to Affect Development of Future Schizophrenia Agents

Investigators from Scripps Research Institute, FL—who published their study results earlier this week in the Journal of Neuroscience—have shown, for the first time, that serotonin mediates biological functions through the use of a specialized signaling pathway that is different from the pathways used by hallucinogens. The study authors feel their findings could have “a profound effect on the development of new therapies” for several disorders, including schizophrenia.

"Our study shows that while both serotonin and hallucinogens act at the serotonin 2A receptor, serotonin utilizes a very specific pathway and its actions are independent of those produced by hallucinogens," said Laura Bohn, associate professor, Florida campus of The Scripps Research Institute. "Future drug discovery efforts to identify lead compounds for treatment of depression may consider focusing upon those that only engage that pathway. This work may also lend insight into the mechanisms that underlie the hallucinations that occur in schizophrenia."

A Blood Test for Schizophrenia

Clinicians will find a new aid in the confirmation of a diagnosis of recent-onset schizophrenia with the newly launched VeriPsych, a blood-based diagnostic test from Rules-Based Medicine.

Intended for use in patients without co-morbidities, like diabetes of autoimmune disease, the test simultaneously measures 51 protein and hormone biomarkers using a mathematical decision rule to compare the biomarker profile of a patient suspected of having schizophrenia with that of patients with a confirmed schizophrenia diagnosis.

Antipsychotic Switching Prevalent in Schizophrenia

With a knowledge that some patients with schizophrenia need to change their antipsychotic medication because of poor response, intolerance, or other reasons and limited data “from naturalistic clinical settings on the frequency of antipsychotic switching, as well as the timing and predictors of such medication changes,” researchers reporting in BMC Psychiatry have confirmed that antipsychotic switching is common in this population.

What’s more, the team has reported that such switching can be predicted by only a few variables, four at baseline and two during early treatment. Women were 37.6% more likely than men to switch, patients with pre-existing depression were 48.4% more likely than patients without, those who had received an antipsychotic in the year leading up to the study were 38.3% less likely to switch than those who hadn’t, and participants with a substance use disorder were 26.9% less likely to switch that those without such disorders. Additionally, “for every 1-point increase in the positive and negative syndrome scale (PANSS) depression/anxiety subscale score, the risk for switching increased by 5.1%, and for every 1-point increase in the Barnes Akathisia objective score, the risk for switching increased by 34.5%.”

The researchers concluded, “Switching antipsychotics appears to be prevalent in the naturalistic treatment of schizophrenia and can be predicted by a small and distinct set of variables. Further longitudinal studies are needed to evaluate and replicate these findings."