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Scale for the Assessment of Positive Symptoms (SAPS)
Please email the author for information about obtaining the instrument: Dr. Nancy Andreasen,
Supplemental: Parkinson's Disease (PD)
Short Description of Instrument
The Scale for the Assessment of Positive Symptoms (SAPS) was originally designed to assess positive symptoms of schizophrenia that fall into four domains: hallucinations, delusions, bizarre behavior, and formal thought disorder (Andreasen, 1984).
The SAPS is linked closely to the Scale for the Assessment for Negative Symptoms (SANS).
Comments/Special Instructions
The SAPS is a structured clinical interview that covers 30 items plus a global rating in the domains/subscales of: hallucinations (7 items), delusions (13 items), bizarre behavior (5 items), and positive formal thought disorder (9-items). The SAPS has been used in Parkinson's Disease populations and is a recommended scale for use in Parkinson's Disease Psychosis by a Movement Disorder Society Task Force in 2008 based on its use in studies of PD and its satisfactory clinimetric assessment albeit not in PD populations (Fernandez et al.).
There are different forms of the SAPS for use specifically in PD including the SAPS-PD, a shortened version for PD with psychosis, and the eSAPS-PD, the enhanced Scale for the assessment of Positive Symptoms in PD.
Scoring and Psychometric Properties
Scoring: Each SAPS item is scored on a 6-point Likert-type scale (0-5):
0 = None/None at all
1 = Questionable
2 = Mild
3 = Moderate
4 = Marked
5 = Severe
The sum of the 4 global domains (hallucinations, delusions, bizarre behavior, and formal thought disorder) produces a summary score of 0-20, and the sum of the 30 individual items provides a composite score of 0-150.
Psychometric Properties: Psychometric properties are not available in PD.
Strengths: The SAPS has been shown to be sensitive to change in clinical trials for PD psychosis (Voss et al., 2010).
Weaknesses: The SAPS clinical interview is time consuming (>30 minutes) and requires a trained clinical interviewer. The SAPS is not designed to assess the full spectrum of psychotic features in PDP such as presence and passage hallucinations, and illusions. The SAPS domains such as bizarre behavior and formal thought disorder may not be as relevant to PDP. The SAPS may not appropriate for use in those with dementia. No psychometric properties are available in PD.
Key Reference:
Andreasen NC. Scale for the assessment of positive symptoms (SAPS). Iowa City, Iowa: University of Iowa; 1984.
Additional References:
Fernandez HH, Aarsland D, FÉnelon G, Friedman JH, Marsh L, TrÖster AI, Poewe W, Rascol O, Sampaio C, Stebbins GT, Goetz CG.  Scales to Assess Psychosis in Parkinson's Disease. Mov Disord. 2008 Mar 15;23(4):484-500.
Voss TS, Brocht AF, Ravina B. Performance of the scale for assessment of positive symptoms in Parkinson's disease psychosis. Mov Disord. 2010 Jan 15;25(1):124-5.
Document last update August 2022