The Immune and Metabolic Factors of Schizophrenia

Schizophrenia occurs in late adolescence or early adulthood with a median incidence of 15 per 100,000 person years and rate ratio somewhat higher in males[1,2]. The symptoms of schizophrenia include positive symptoms that embody classic psychosis, such as sensory hallucinations, delusions or disorganized thinking and negative symptoms include lack of emotional response (blunted affect), unprompted speech (alogia) and motivation (avolition). Patients with schizophrenia also experience cognitive dysfunction, impaired attention and executive function; emotional and behavioural difficulties with intellectual and language alterations, as well as subtle motor delays [3]. While some patients may only experience one psychotic episode, many will follow a relapsing course over their lifetime [4]. The lifespan of patients with schizophrenia is shortened by up to 25 years, the cause of which likely includes suicide, lifestyle risk factors, cardiovascular disease and obesity amongst others [5,6]. Clinical diagnosis of schizophrenia is made using criteria specified in the Diagnostic and Statistical Manual of Mental Disorders 5 (DSM‐5) and International Classification of Diseases‐10 (ICD‐10). Structural brain abnormalities occur in schizophrenia but are not sensitive enough (approximately 40‐50% patients) or specific enough (seen in approximately 10% of normal controls) to be of diagnostic benefit [7]. At present, there is also no evidence‐based biomarker to diagnose schizophrenia currently in practice and the biological entity of schizophrenia is based on patient introspection and clinical observation. Moreover, while Abstract