A study led by University of North Carolina researchers represents an important step forward in the accurate diagnosis of people who are experiencing the earliest stages of psychosis.
Psychosis includes hallucinations or delusions that define the development of severe mental disorders such as schizophrenia. Schizophrenia emerges in late adolescence and early adulthood and affects about 1 in every 100 people. In severe cases, the impact on a young person can be a life compromised, and the burden on family members can be almost as severe.
The opensource study published in the journal Schizophrenia Bulletin reports preliminary results showing that a blood test, when used in psychiatric patients experiencing symptoms that are considered to be indicators of a high risk for psychosis, identifies those who later went on to develop psychosis.
The study included eight sites as part of the North American Prodrome Longitudinal Study (NAPLS 2). The NAPLS 2 project is a multi-site endeavor that aims to better understand predictors and mechanisms for the development of psychosis. In the current study, the team measured expression of plasma analytes reflecting inflammation, oxidative stress, hormones, and metabolism in 765 patients classed as ‘clinical high-risk’ to suffer psychosis and 280 ‘low-risk’ patients in the same demographic, both groups were aged between 12 and 35.
Out of the original cohort followed over a 2-year period, 32 clinical high risk patients developed psychosis, and 35 patients from the low-risk group also developed psychosis. Both groups were compared with the newly developed control group of 40 patients who did not develop psychosis.
The blood test included a selection of 15 measures of immune and hormonal system imbalances as well as evidence of oxidative stress from an orginal 185 assay-test. The fifteen analytes were selected with the help of a ‘greedy algorithm’ computer program after analytes with relation to the use of antipsychotics, antidepressants, marijuana, nicotine, or alcohol were excluded. The remaining 15 biomarkers were shown to be present in 90% of the 107 subjects.
The team state that while further research is required before this blood test could be clinically available, these results provide evidence regarding the fundamental nature of schizophrenia, and point towards novel pathways that could be targets for preventative interventions.
Modern, computer-based methods can readily discover seemingly clear patterns from nonsensical data. Added to that, scientific results from studies of complex disorders like schizophrenia can be confounded by many hidden dependencies. Thus, stringent testing is necessary to build a useful classifier, both of which the team has done via the use of ‘greedy algorithms’. A greedy algorithm is an algorithm that follows the problem solving heuristic of making the locally optimal choice at each stage and is used extensively in bioinformatics to solve a variety of problems.
The study concludes that the multiplex blood assay, if independently replicated and if integrated with studies of other classes of biomarkers, has the potential to be of high value in the clinical setting.