The term “psychotic disorders” refers to a broad conceptualization of conditions including primary psychoses, such as schizophrenia and psychotic mood disorders, other disorders that are sometimes marked by psychotic features (e.g., borderline personality disorder, body dysmorphic disorder), and secondary psychotic disorders due to medical conditions or substances (e.g., alcohol withdrawal delirium). As addressed in Ketter, et al. 2004 (“Psychotic Bipolar Disorders: Dimensionally Similar to or Categorically Different from Schizophrenia?,” cited in the Debate of Dimensional versus Categorical), controversy regarding relationships among mood disorders (particularly bipolar and depressive disorders with psychotic features) and schizophrenia is ongoing. The authors argue that while the respective dimensional (e.g., psychotic bipolar disorder as intermediate between non-psychotic bipolar and schizophrenia spectrum disorders) versus categorical debate persists, a mixed dimensional/categorical approach may best help elucidate pathophysiology and treatment options. Schizophrenia, specifically, is a severe and persistent form of mental illness often marked by positive symptoms (such as excesses and distortions in thoughts and sensory/perceptual experiences such as hallucinations and delusions), negative symptoms (behavioral deficits such as avolition, asociality, anhedonia, blunted affect, and alogia), disorganized symptoms (such as disorganized speech and behavior), movement symptoms (or grossly abnormal psychomotor behavior such as catatonia), and impairments in cognition (such as memory and frontal/executive functions that include, for example, planning ability and initiation). Kring, et al. 2014 (Abnormal Psychology, cited under the Schizophrenia Spectrum) provides an excellent introductory-level overview of schizophrenia and other psychotic disorders. The etiological (or causal) basis of schizophrenia and related psychotic disorders remains not wholly determined. Prevailing theories, however, ascribe to a diathesis-stress model, whereby biological factors (e.g., predispositions such as genetic liability) are believed to interact with adverse environmental factors (e.g., obstetric complications; adverse, stressful life events) over the course of development toward the manifestation of illness. This article offers a historical perspective of psychotic disorders, a review of etiological/theoretical models, a description of illness epidemiology and issues pertaining to sex differences and comorbidity, an outline of diagnostic considerations, a description of the schizophrenia spectrum, an examination of available assessment tools, the role of cognition/social cognition, a review of current evidence of neurobiological disruptions in psychosis (e.g., genetics, structural and functional neuroimaging, hormones, neurotransmitters, other aspects of maldevelopment in the central nervous system), other laboratory markers (e.g., perceptual and attentional abnormalities, smooth-pursuit eye movement dysfunction), environmental factors (such as stress, toxins, and familial-expressed emotion), the importance of gene-environment interactions in psychotic disorders, and, finally, current directions pertaining to prevention and treatment (pharmacological and psychosocial). While various psychotic-related disorders are addressed, this article focuses on the schizophrenia spectrum.
