Neuropsychology of subjects with ultra-high risk (UHR) of psychosis: A critical analysis of the literature.

Cognitive disorders are currently considered as central components of disorders found in schizophrenia and are a major handicap for patients day to day. These disorders appear before the first psychotic episode, in the prodromal phase, during which time the symptoms are below the threshold for psychosis. People with these symptoms are considered as presenting an at-risk mental state (or at ultra-high risk, UHR of psychosis) and their risk for psychotic transition is between 20% and 40% within one year. Despite a number of studies, the chronology in which cognitive disorders appear in relation to the psychotic symptoms has not clearly been established and the study of the links between cognition and symptoms could improve our understanding of psychotic disorders. The detection of certain cognitive disorders before the onset of psychotic disorders could help improve early detection. We carried out a systematic analysis of the literature exploring cognitive disorders found in subjects with UHR for psychosis. The objective of most studies was to establish the predictive value for psychotic transition. Nevertheless study results have shown little consensus. Faced with this heterogeneity of results from past studies, we carried out a critical analysis of the literature and suggest areas of reflection for future research.

[Stress and psychotic transition: A literature review]. / Stress et transition psychotique : revue de la littérature.

BACKGROUND: Psychiatric disorders are consistent with the gene x environment model, and non-specific environmental factors such as childhood trauma, urbanity, and migration have been implicated. All of these factors have in common to dysregulate the biological pathways involved in response to stress. Stress is a well-known precipitating factor implicated in psychiatric disorders such as depression, bipolar disorder, anxiety, and possibly schizophrenia. More precisely, psychosocial stress induces dysregulation of the hypothalamic-pituitary-adrenal axis (HPA) and could modify neurotransmission, which raises the question of the involvement of stress-related biological changes in psychotic disorders. Indeed, the literature reveals dysregulation of the HPA axis in schizophrenia. This dysregulation seems to be present in the prodromal phases (UHR subjects for ultra-high risk) and early schizophrenia (FEP for first episode psychosis). Thus, and following the stress-vulnerability model, stress could act directly on psychotic onset and precipitate the transition of vulnerable subjects to a full-blown psychosis. OBJECTIVE: The present paper reviews the literature on stress and onset of schizophrenia, with consideration for the causal role vs. associated role of HPA axis dysregulation in schizophrenia and the factors that influence it, in particular during prodromal and earlier phases. We also discuss different methods developed to measure stress in humans. METHODOLOGY: We performed a bibliographic search using the keywords 'cortisol', 'glucocorticoid', 'HPA' with 'UHR', 'CHR', 'at-risk mental state', 'first episode psychosis', 'schizotypal', 'prodromal schizophrenia' in Medline, Web of Knowledge (WOS), and EBSCO completed by a screening of the references of the selected articles. RESULTS: Stress has been studied for many years in schizophrenia, either by subjective methods (questionnaires), or objective methods (standardized experimental protocols) with biological sampling and/or brain imaging methods. These methods have suggested a link between dysregulation of the HPA axis and psychotic symptoms both through abnormal basal levels of cortisol and flattened reactivity to social stress. Imaging results suggest indirect modifications, including abnormal pituitary or hippocampal volume. Several factors dysregulating the HPA axis have also been highlighted, such as consumption of drugs (i.e. cannabis), childhood trauma or genetic factors (such as COMT, or MTHFR variants). Psychological stress induces subcortical dopaminergic activation attributable to hypothalamic-pituitary-adrenal (HPA) axis dysregulation. This dysregulation is present in the prodromal phase (UHR) in patients who have experienced a first psychotic episode (FEP) and in siblings of schizophrenic patients. Stress dysregulation is a plausible hypothesis to understand the psychosis onset. DISCUSSION: The effect of stress on brain pathways could participate to the mechanisms underlying the onset of psychotic symptoms, both as a precipitating factor and as a marker of a predisposing vulnerability. This dysregulation fits into the gene x environment model: in subjects with genetic predispositions, stressful environmental factors can modify biological pathways implicated in psychiatric disorders, promoting the emergence of symptoms. However, many confounding factors obscure the literature, and further studies are needed in schizophrenic patients, UHR and FEP patients to clarify the precise role of stress in psychotic transition. Identification of stress biomarkers could help diagnosis and prognosis, and pave the way for specific care strategies based on stress-targeted therapies.

Development of a blood-based molecular biomarker test for identification of schizophrenia before disease onset.

Recent research efforts have progressively shifted towards preventative psychiatry and prognostic identification of individuals before disease onset. We describe the development of a serum biomarker test for the identification of individuals at risk of developing schizophrenia based on multiplex immunoassay profiling analysis of 957 serum samples. First, we conducted a meta-analysis of five independent cohorts of 127 first-onset drug-naive schizophrenia patients and 204 controls. Using least absolute shrinkage and selection operator regression, we identified an optimal panel of 26 biomarkers that best discriminated patients and controls. Next, we successfully validated this biomarker panel using two independent validation cohorts of 93 patients and 88 controls, which yielded an area under the curve (AUC) of 0.97 (0.95-1.00) for schizophrenia detection. Finally, we tested its predictive performance for identifying patients before onset of psychosis using two cohorts of 445 pre-onset or at-risk individuals. The predictive performance achieved by the panel was excellent for identifying USA military personnel (AUC: 0.90 (0.86-0.95)) and help-seeking prodromal individuals (AUC: 0.82 (0.71-0.93)) who developed schizophrenia up to 2 years after baseline sampling. The performance increased further using the latter cohort following the incorporation of CAARMS (Comprehensive Assessment of At-Risk Mental State) positive subscale symptom scores into the model (AUC: 0.90 (0.82-0.98)). The current findings may represent the first successful step towards a test that could address the clinical need for early intervention in psychiatry. Further developments of a combined molecular/symptom-based test will aid clinicians in the identification of vulnerable patients early in the disease process, allowing more effective therapeutic intervention before overt disease onset.