Vibrational Spectroscopy as a Tool to Diagnose Psychiatric and Neurodevelopmental Disorders, Through Chemometrics Analysis of Spectral Data of Blood Plasma Samples

Abstract

It is well known that neurodegenerative illnesses like Alzheimer’s, which are associated with loss of cognitive functions, have been amplifying their impact on society with the increase of the lifetime expectation achieved in the last few decades. But also in the case of psychiatric and neurodevelopmental disorders for which aging is not a dominant factor (like, for example, autism, schizophrenia and bipolar diseases), the demands of the modern life have augmented their societal importance. Unfortunately, most of these types of diseases are of difficult clinical diagnosis due to the heterogeneity of their symptoms, what leads to errors in the initial diagnosis, for example of the bipolar disorder, close to 70%, with more than 30% of patients remaining misdiagnosed for at least 10 years. Altemative/complementary strategies that may help clinicians to improve these numbers are then of great relevance, in particular when they rely in fast and cheap analytical procedures having a molecular basis. Use of spectroscopic methods for accomplishment of this goal, through analysis of body fluids and identification of biomarker-related spectroscopic features, appears as a promising approach to this problem. In fact, this approach has been shown to be appropriate for helping diagnosis of other types of diseases, like cancer and infectious diseases, for example. In this investigation, vibrational spectroscopy (both infrared absorption - 1R - and Raman scattering), has been selected as analytical technique for trial diagnosis of a series of disorders affecting the cognitive functions. Vibrational spectroscopy is a veiy sensitive analytical method to sample composition and variability; it allows fast and cheap analyses and, when the object of analysis is a body fluid, the tests can be performed without requiring patients’ multiple visits to the health units (in contrast with the clinical traditional methods). The present program of studies focusses on the analysis of blood plasma samples of patients clinically diagnosed as bearing psychiatric or neurodevelopmental disorders, in order to find proper biomarker- related spectroscopic features that can help a correct diagnosis. Chemometrics is used to perform the analysis of the spectroscopic data obtained by 1R or Raman spectroscopies, in the search for a reliable statistical model to discriminate and classify the patients according to their disease. In this poster, the results obtained for the case of autism will be presented, together with the plan designed for the ongoing studies focusing on other types of illnesses, in particular, schizophrenia and bipolar diseases (including subgroups: bipolar depressive episode, manic episode and otimic), as well the relevant information about the research consortium established to undertake these studies. It will be shown that the information contained in the infrared spectra of blood samples of autistic patients allowed for their correct classification against the control group, thus testifying the potential of the used methodology for the aimed purposes.