Schizotypal Personality Disorder

Schizotypal personality disorder (STPD) is classified as a Cluster A (odd or eccentric) personality disorder in DSM-5 and is recognized as part of the schizophrenia spectrum disorders due to genetic, neurobiological, and clinical similarities with schizophrenia. Prevalence estimates range from 3-5% in general population with slight male predominance. The disorder typically manifests by adolescence or early adulthood and tends to be stable across lifespan, with risk of progression to schizophrenia in 10-20% of cases.

Pathogenesis involves genetic factors (familial relationship with schizophrenia spectrum disorders), neurodevelopmental abnormalities, dopaminergic dysregulation, structural brain changes (reduced volume in prefrontal cortex and temporal lobes similar to schizophrenia but to lesser degree), early childhood trauma, neglect, and maladaptive attachment styles. Patients show preserved reality testing distinguishing them from schizophrenia, but exhibit attenuated psychotic-like experiences, mild cognitive deficits, and prominent social-cognitive impairment.

Diagnostic criteria require pervasive pattern of social and interpersonal deficits with at least five of the following: ideas of reference, odd beliefs or magical thinking inconsistent with cultural norms, unusual perceptual experiences (illusions), odd thinking and speech, suspiciousness or paranoid ideation, inappropriate or constricted affect, behavior or appearance that is odd, eccentric, peculiar, lack of close friends or confidants other than first-degree relatives, and excessive social anxiety. Treatment combines psychotherapy (cognitive behavioral therapy, supportive therapy, social skills training, schema therapy), low-dose antipsychotic medication for cognitive-perceptual symptoms, antidepressants for depression and anxiety, and treatment of comorbid conditions. Outcomes vary with stable course, episodes of psychotic decompensation, and progression to schizophrenia in subset of patients.