Assessing the validity of the Wechsler Adult Intelligence Scale (WAIS-IV) in predicting completion in a long-term residential rehabilitation for substance use problems

Abstract

Background

We aimed to examine the predictive validity of the Weschler Adult Intelligence Scale (WAIS-IV) in predicting treatment completion, over and above educational status.

Methods

One hundred and ninety-six (N = 196) individuals from the Odyssey House Residential Rehabilitation Program, NSW, Australia between 2010 and 2016 were administered a structured interview including substance use disorders and the Verbal Comprehension (VCI), Perceptual Reasoning (PRI), Working Memory (WMI), and Processing Speed (PSI) domains of the WAIS-IV.

Results

There were significant differences between our clinical sample and the population norm with respect to the proportion below the mean for PSI (z = 12.27, p < .001), VCI (z = 2.33, p < .02) but not for WMI (z = 1.67, p < .10) or PRI (z = −1.76, p < .08). The WAIS-IV subscales did not significantly predict treatment completion (p’s > .16) over and above educational status (p < .01).

Conclusions

Our findings suggest that in clients in drug and alcohol rehabilitation settings a combination of skills may be impacted including Verbal Comprehension and Processing Speed. Moreover, our findings also suggest that WAIS-IV subscales do not predict treatment completion in a drug and alcohol residential setting, over and above a brief assessment of educational status.

Keywords:

• Cognitive functioning
• rehabilitation
• substance use
• treatment
• WAIS

Acknowledgements

The authors would like to acknowledge the contribution of Jennifer Meyer (psychologist at Odyssey House) and Carmen Iancu (psychologist and clinical manager at Odyssey House).

Authors’ contributions

A.S. designed the study, completed the assessments and contributed to writing the manuscript. L.M. contributed to data analysis and writing of the manuscript. K.M., T.H. and W.L. contributed to writing the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).