What is schizophrenia - symptomatology

Schizophrenia is a highly heterogenous disorder with substantial interindividual variationin how the illness is experienced and how it presents clinically. The disorder is composedof primary symptom clusters-positive symptoms, negative symptoms, disorganization,neurocognitive deficits, and social cognitive impairments. These, along with duration,severity, and excluding other possible etiologies, comprise the diagnostic criteria for thedisorder outlined in the two commonly used diagnostic classification systems-theDiagnostic Statistical Manual of Mental Disorders, Fifth Edition, Text Revision andthe International Classification of Diseases, 11thRevision. These primary symptoms aswell as accessory symptoms (mood disturbances, anxiety, violence) and comorbidities(substance use, suicidality) bear upon each other to varying degrees and impact func-tional outcomes. The following review presentstwo patient cases illustrating the clinicalheterogeneity of schizophrenia, the natural history of the illness and diagnosis, followedby the current understanding of the primary symptom clusters, accessory symptoms, andcomorbidities. In addition to noting symptom prevalence, onset, and change over time,attention is paid to the impact of symptoms on functional outcome.