Acute and transient psychotic disorder and schizotypal disorder

Definition of psychosis

 * describes an altered touch with reality (what is real? what not?)
 * can have psychiatric causes (e.g. schizophrenia), organic causes (e.g. tumor) or be due to intoxication (e.g. LSD)

ICD-10 Criteria for acute and transient psychotic disorders

 * Begin acutely
 * polymorphic symptoms: quickly changing
 * presence of typical schizophrenic symptoms

Subtypes according to the ICD-10

 * acute polymorphic psychotic disorder with or without schizophrenia
 * Acute schizophrenia-like psychotic disorder
 * Other acute predominantly delusional psychotic disorders
 * comparatively stable delusions or hallucinations
 * delusions of persecution or reference
 * for less than 3 months (i.e. not persistent delusional disorder)
 * Paranoid reaction, psychosis

DSM-V: Brief psychotic disorder

 * Is essentially the same as F23 (just much easier and more logical)
 * Psychosis present for 1 day to 1 month : schizophrenic symptoms

Schizotypal disorder ( a schizophrenia spectrum disorder)

 * Diagnostics : according to the DSM-5
 * At least 5 of the following criteria have to be met:
 * Odd and eccentric behavior or physical appearance
 * Magical thinking: the invention of causal relationships between behaviors and events that is inconsistent with an individual's cultural norms (e.g., believing that thoughts are able to control reality)
 * Social awkwardness
 * Excessive social anxiety
 * Ideas of reference
 * Unusual perceptual experiences (e.g., body illusions)
 * Bizarre thinking/speech (e.g., metaphorical, overelaborate)
 * Paranoia and suspicion of others
 * Constricted affect
 * Few or no close friends
 * Social anxiety and preference for social isolation because of paranoia