Study: CPT Is Not Accurate ADHD Assessment Tool for Adults
The Continuous Performance Test (CPT), a popular neuropsychological test for assessing the severity of ADHD, is found to be an unreliable symptom gauge for adults.
March 14, 2019
The Continuous Performance Test (CPT) — a common neuropsychological gauge of continuous attention — is not a reliable tool for assessing the severity or presentation of ADHD symptoms in adults. This was the finding of a study published recently in The Journal of Attention Disorders that studied CPT1 in hopes of resolving existing mixed evidence on the usefulness and reliability of this and other neuropsychological evaluations.
For the study, 201 adult ADHD patients were selected from a specialized center for ADHD diagnosis and treatment at the Geneva University Hospitals in Switzerland. Participants completed a screening in their own home, then a psychologist or psychiatrist administered both a CPT and an interview to assess ADHD symptom severity.
While there were some notable associations between ADHD and CPT variables, they were of small magnitude, leading researchers to conclude that the CPT did not produce relevant information on adults with ADHD. According to the expert evaluation, 64.2% of the participants had the mixed or hyperactive presentation and 35.8% had the inattentive presentation. However, the CPT results showed that only 51.7% were classified as likely to have ADHD — 40.3% of those with hyperactive and mixed presentations, and 58.1% with the inattentive presentation.
The test failed to discriminate between ADHD presentations with a high classification error rate for hyperactive (22.5%) and an unacceptable rate for inattentive (80.3%). This failure to accurately identify ADHD confirms the CPT’s lack of specificity and its high rates of false negatives. Researchers also concluded the CPT is not the most reliable tool for treatment monitoring and its findings should be interpreted with caution.
The study’s main complicating factor was that some participants had comorbidities capable of influencing their CPT performance. However, similar findings were noted when the analysis controlled for medications and comorbidities.
1 Baggio, S., Hasler, R., Giacomini, V., El-Masri, H., Weibel, S., Perroud, N., & Deiber, M.-P. Does the Continuous Performance Test Predict ADHD Symptoms Severity and ADHD Presentation in Adults? Journal of Attention Disorders (Jan. 2019). https://doi.org/10.1177/1087054718822060