TITLE:
Biomarker Symptom Profiles for Schizophrenia and Schizoaffective Psychosis
AUTHORS:
Stephanie Fryar-Williams, Jörg E. Strobel
KEYWORDS:
Biomarkers, Schizophrenia, Psychosis, Mental Illness, Symptom-Profiles
JOURNAL NAME:
Open Journal of Psychiatry,
Vol.5 No.1,
January
28,
2015
ABSTRACT: Background: Neuroscience
can assist clinical understanding and therapy by finding neurobiological
markers for mental illness symptoms. Objectives: To quantify biomarkers for
schizophrenia and schizoaffective disorder and relate these to discrete
symptoms of psychosis. Methods: Within a case-control design with multiple
exclusion criteria to exclude organic causes and confounding variables, 67 DSM
IV-R diagnosed and 67 control participants from a defined hospital, clinic and
community catchment area were investigated for candidate markers. Participants
underwent protocol-based diagnostic-checking and symptom rating via Brief
Psychiatric Rating Scale and Positive and Negative Syndrome Scale,
functional-rating scales, biological sample-collection and sensory-processing
assessment. Blood and urine samples were analysed for monoamine
neurotransmitters, their metabolites, vitamin cofactors and
intermediate-substances related to oxidative stress and metabolism of
monoamines. Neurocognitive assessment of visual and auditory processing was
conducted at both peripheral and central levels. Biomarkers were defined by
Receiver Operating Curve (ROC) analysis. Spearman’s analysis explored
correlations between discrete symptoms and the biomarkers. Results: Receiver
Operating Curve (ROC) analysis identified twenty-one biomarkers: elevated
urinary dopamine, noradrenaline, adrenaline and hydroxy pyrroline-2-one as a
marker of oxidative stress. Other biomarkers were deficits in vitamins D, B6
and folate, elevation of serum B12 and free serum copper to zinc ratio, along
with deficits in dichotic listening, distance vision, visual and auditory speed
of processing, visual and auditory working memory and six middle ear acoustic
reflex parameters. Discrete symptoms such as delusions, hostility, suicidality
and auditory hallucinations were biomarker-defined and symptom biomarker
correlations assumed an understandable pattern in terms of the catecholamines
and their relationship to biochemistry, brain function and disconnectivity.
Conclusions: In the absence of a full diagnosis, biomarker-symptom-signatures
inform psychiatry about the structure of psychosis and provide an
understandable pattern that points in the direction of a new neurobiological
system of symptom-formation and treatment.