The SCI-PSY is based on a spectrum model that emphasizes soft signs, low-grade symptoms, subthreshold syndromes, as well as temperamental and personality traits. The psychotic spectrum considers a psychopathological continuum, ranging from psychotic soft signs, personality disorders (in particular Cluster A, Borderline and Avoidant) to full-blown major psychoses (Schizophrenia, Schizoaffective and Delusional Disorders, Mood Disorders with psychotic features). The instrument includes 164 items coded as yes/no and organized into five domains: paranoid (covering the spectrum features encompassing mild hypervigilance, diffidence, suspiciousness, interpretive attitude and paranoid self-reference); schizotypy-schizoidism (exploring religiosity, superstition, magical and odd thoughts); interpersonal sensitivity (describing the tendency to avoid the others due to the fear of being misunderstood or criticized. This tendency may sometimes extend beyond the limits of interpersonal sensitivity and subjects may loose insight in it); misperceptions (exploring dissociative phenomena and borderline manifestations of full-blown phenomenology of hallucinations and delusions), and typical symptoms (typical DSM-IV symptoms of psychosis). Within each domain more specific subdomains can be identified, that explore self-esteem, fixity of belief, interpretive attitude, hypervigilance, suspiciousness, anger/over-reactivity, fanaticism, depersonalization and derealization, and body illusions.

Scoring

The SCI-PSY instrument consists of 164 items coded as yes/no and divided into five domains.
See algorithm section, below on this page for how to score the instrument.

Psychometric Properties

Discriminant validity: Domains that were identified a priori as characteristics of schizophrenia or schizoaffective disorder (schizoid, typical psychotic symptoms and misperception domains) significantly distinguished subjects with these diagnoses from those with psychotic mood disorders and from all the non-psychotic groups. All diagnostic groups had a significantly higher total score on the SCI-PSY than controls. Reliability: internal consistency assessed using Kuder-Richardson coefficient was >0.50 for all the domains and >0.70 for 12 out of 16 domains. The correlation between domains ranged between 0.39 and 0.77 (p<0.01).

Sbrana A, Dell’Osso L, Benvenuti A, Rucci P, Cassano P, Banti S, Gonnelli C, Doria MR, Ravani L, Spagnolli S, Rossi L, Raimondi F, Catena M, Endicott J, Frank E, Kupfer DJ, Cassano GB: The psychotic spectrum: Validity and reliability of the Structured Clinical Interview for the Psychotic Spectrum. Schizophrenia Research, 75:375-387, 2005.

Note: each items is scored as "0" (NO), "1" (YES).
interpersonal sensitivity	sum of items 36-45
paranoid	hypertrofic self-esteem	sum of items 1-9
	strict thinking	sum of items 22-29
	superstion	sum of items 30-35
	fanaticism	sum of items 46-55
	relations with others	sum of items 56-63
	self-reference	sum of items 64-66, 69-71
	interpretative attitude	sum of items 72-77, 117-118
	suspiciousness	sum of items 78-88, 91-96, 102
	anger/over reactivity	sum of items 97-101, 103-105
	hypervigilance	sum of items 106-116
schizoid	schizoidism-autism	sum of items 10-21
	schizotypy	sum of items 119-127
misperceptions	illusions	sum of items 128-131, 134-135
	depersonalization/derealization	sum of items 132-133
typical symptoms	delusions	sum of items 67-68, 89-90, 136-154
	hallucinations	sum of items 155-162
	catatonia	sum of items 163-164
Total score (sum of domains scores) range 0 - 164 Threshold for total score for any of the instruments: none determined at this time