Assessment & Research

The reliability and validity of general psychotic rating scales with people with mild and moderate intellectual disabilities: an empirical investigation.

Hatton et al. (2005) · Journal of intellectual disability research : JIDR 2005
★ The Verdict

PANSS and PSYRATS work for mild-ID adults, but trust the positive items more than the negative or delusion ones.

✓ Read this if BCBAs who assess or refer adults with intellectual disability and possible psychosis.
✗ Skip if Clinicians working only with severe-ID or non-verbal clients.

01Research in Context

01

What this study did

Researchers tested two common psychosis scales on adults with mild or moderate intellectual disability. They wanted to know if the PANSS and PSYRATS give steady scores and truly catch psychotic signs in this group.

The team checked if the same rater got similar scores on different days. They also looked at whether scores lined up with real-life symptoms that staff reported.

02

What they found

The PANSS and PSYRATS held up well for most parts. Positive-symptom and hearing-voices items were the clearest flags.

Negative-symptom and fixed-belief items were shakier. Clinicians need to double-check those sections before making choices.

03

How this fits with other research

Alsop et al. (1995) did an earlier test of the PIMRA schizophrenia subscale in similar adults. Their good results set the stage for trying newer tools like the PANSS.

Vereenooghe et al. (2013) pooled later therapy studies and showed CBT helps with anger and depression in this same group. Their review leaned on sound tools, so the 2005 PANSS data give extra confidence to those future trials.

Barthelemy et al. (1989) found that over one-third of adults with ID have a mental health disorder. That high rate means you need dependable scales like these to spot who needs help.

04

Why it matters

You can now grab the PANSS or PSYRATS when a client with mild ID reports odd experiences. Treat positive and hallucination scores as solid red flags. Pause and gather more evidence if negative or delusion scores seem off. This saves you from both missed illness and false labels.

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Try the PANSS positive subscale first when a client with mild ID mentions hearing voices.

02At a glance

Intervention
not applicable
Design
other
Sample size
62
Population
intellectual disability
Finding
positive
Magnitude
medium

03Original abstract

BACKGROUND: Whilst assessment tools have been developed to diagnose schizophrenia in people with mild intellectual disabilities (IDs), little attention has been paid to developing reliable and valid dimensional measures of psychotic experiences with this population. This study investigates the reliability and validity of two such measures developed for the general adult psychiatric population, the Positive and Negative Syndrome Scale (PANSS) and the Psychotic Symptom Rating Scales (PSYRATS), with a population of adults with mild IDs. METHOD: Sixty-two adults with mild IDs were interviewed using the PANSS and PSYRATS, and independently interviewed using the Psychiatric Assessment Schedule--Adults with Developmental Disability (PAS-ADD) to obtain psychiatric diagnoses to the criteria of the International Classification of Diseases--Tenth Revision (ICD-10). On the basis of ICD-10 diagnosis, participants were divided into three groups: psychosis (n=11); other mental health problem (n=14); no mental health problem (n=37). PANSS and PSYRATS subscale scores were compared across these three groups and were correlated with PAS-ADD symptom scores across a number of PAS-ADD symptom domains. RESULTS: All PANSS and PSYRATS subscales showed adequate internal reliability, largely good test-retest reliability, and logical inter-correlations between subscales. The PANSS positive symptoms and the PSYRATS auditory hallucinations subscales differentiated between the psychosis group and the other groups; the PANSS general symptoms subscale differentiated between the psychosis and no mental health problem groups; and the PANSS negative symptoms and the PSYRATS delusions subscales did not differentiate between the three groups. CONCLUSIONS: The PANSS and PSYRATS are promising measures for use with people with mild IDs and psychotic experiences, although further investigation of items relating to negative symptoms and delusions is warranted.

Journal of intellectual disability research : JIDR, 2005 · doi:10.1111/j.1365-2788.2005.00696.x