Using Screening Questionnaires to Diagnose Adult ADHD
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McCann B.S. Screening and diagnostic utility of self-report attention deficit hyperactivity disorder scales in adults. Comprehensive Psychiatry 2004; 45(3):175-83.
How effective are standard adult ADHD scales in screening and aiding in diagnosis? (Adult Rating Scale (ARS), Attention-Deficit Scales for Adults (ADSA) and Symptom Inventory for ADHD)
Background: The estimated prevalence of ADHD in the adult population is between 0.3% and 5%. Currently, there are several scales available for screening and diagnosing ADHD in adults. However, despite their frequent use, few studies have explored the validity and reliability of these scales.
Question Type: Diagnosis.
Validity Criteria:
In this study, the diagnosis of PTSD was uncertain in participants and there was a blind comparison between the results of the screening questionnaires and the determination of clinicians based on a semi-structured interview (gold standard). Every participant completed all three questionnaires as well as a semi-structured interview and follow up was complete. The main threat to validity involved the population selected for screening. Participants were recruited from an adult specialty ADHD clinic. Patients were either self referred secondary to significant ongoing symptoms or seeking a second opinion on a previously applied diagnosis.
Study Design: Cross Sectional
Criteria for Appropriate Design:
This study was conducted in a university affiliated adult ADHD specialty clinic in the Seattle area from 1997 to 1999. A total of 82 patients participated in the study the majority of which were Caucasian males (96.3% and 59.8% respectively). Each participant completed three commonly utilized screening questionnaires: the Adult Rating Scale (ARS), the Attention-Deficit Scale for Adults (ADSA) and the Symptom Inventory for ADHD. In addition, each participant underwent two semi-structured interviews conducted by a psychologist and a psychiatrist. The consensus of these interviewers served as the gold standard of diagnosis. Based on the interviews, the clinicians were able to assign any DSM-IV diagnosis.
Main results:
Based on the diagnostic interview, 38 patients were diagnosed with ADHD while 44 were given an alternative diagnosis. Depressive disorder (25%), dysthymia (22.7%) and bipolar disorder (11.4%) were the principal alternative diagnoses. Based on these results, the following sensitivities, specificities and likelihood ratios were determined.
| Test | Score | Sens | Spec. | Positive Likelihood Ratio | Negative Likelihood Ratio |
|---|---|---|---|---|---|
| Symptom Inventory | 6 | 78.4 | 53.5 | 1.7 | 0.40 |
| 7 | 62.2 | 67.4 | 1.9 | 0.56 | |
| ARS | 31 | 91.9 | 32.6 | 1.4 | 0.25 |
| 41 | 59.5 | 58.1 | 1.4 | 0.70 | |
| ADSA | T-score 70 | 81.0 | 46.0 | 1.5 | 0.35 |
Conclusions:
Although many self report indices are currently available to aid in the screening and diagnosis of adult ADHD, these studies yield a large number of false positives that limit their clinical usefulness. In particular, patients with mood disorders may share a number of characteristics with ADHD that make them more vulnerable to inappropriate diagnosis and potentially harmful medication. The results of this study clearly demonstrate the limits of self report indices in screening and diagnosing ADHD. However, their potential role in monitoring the symptoms of ADHD in patients previously diagnosed remains unclear and should be a topic for further research.
Synopsis:
In this cross-sectional study, the positive and negative predictive values of the Adult Rating Scale (ARS), the Attention-Deficit Scale for Adults (ADSA) and the Symptom Inventory for ADHD were shown to produce minimal or no change in the pretest likelihood of ADHD. Additionally, the study showed that individuals with mood disorders were particularly vulnerable to inappropriate diagnosis.
Presented by Doug Burgess, MD on 3/26/07
Comments:
Very nice summary table.
