Chapter 11: Psychotic Disorders

The discussion distinguishes between primary psychotic conditions such as schizophrenia, schizoaffective disorder, and delusional disorder, and secondary psychoses arising from medical illnesses, neurological conditions, or substance use. The core phenomenology of psychosis encompasses hallucinations, delusions, disorganized thought patterns, and cognitive impairment that significantly compromise functional capacity. The chapter explores the neurobiological mechanisms underlying psychotic symptoms, particularly the dopamine hypothesis which posits excessive dopaminergic activity in mesolimbic pathways contributes to positive symptoms, alongside the glutamate dysfunction model suggesting hypofunction of N-methyl-D-aspartate receptor signaling. Structural brain abnormalities including ventricular enlargement and gray matter reduction are examined as potential biological markers. Schizophrenia symptomatology is organized into distinct clusters: positive symptoms reflecting excess or distortion of normal experiences, negative symptoms involving diminishment of emotional expression and motivation, cognitive deficits affecting attention and executive function, and disorganization of behavior and speech. The natural disease progression is characterized by prodromal phases with emerging subclinical symptoms, active psychotic episodes, and residual phases with residual impairment. Pharmacological management focuses on antipsychotic medications, differentiating between typical first-generation agents that primarily block dopamine D2 receptors and atypical second-generation antipsychotics with broader receptor binding profiles and potentially superior tolerability. The chapter addresses both therapeutic efficacy and adverse effects including metabolic complications, movement disorders, and cardiovascular risks. Psychosocial interventions including cognitive-behavioral therapy, family-based approaches, and psychoeducation are presented as essential complements to pharmacotherapy for optimizing functional recovery and quality of life.