By the book: ADHD prevalence in medical students varies with analogous methods of addressing DSM items.

Objective: The marked increase in the prevalence of attention-deficit/hyperactivity disorder (ADHD) among university students gives rise to questions about how best to diagnose in this setting. The aim of the present study was to calculate ADHD prevalence in a large non-clinical sample of medical students using a stepwise design and to determine whether ADHD diagnosis varies if interviewees use additional probing procedures to obtain examples of positive DSM items.
Methods: A total of 726 students were screened with the Adult Self-Report Scale (ASRS) and invited for an interview with the Kiddie Schedule for Affective Disorders and Schizophrenia (K-SADS) adapted for adults.
Results: The ASRS was positive for 247 students (37%), although only 83 (7.9%) received an ADHD diagnosis. ASRS sensitivity and specificity rates were 0.97 and 0.40, respectively. Probing procedures were used with a subgroup of 226 students, which decreased the number of ADHD diagnoses to 12 (4.5%).
Conclusion: Probing for an individual's real-life examples during the K-SADS interview almost halved ADHD prevalence rate based on the ASRS and K-SADS, which rendered the rate consistent with that typically reported for young adults. In reclassified cases, although examples of inattention did not match the corresponding DSM item, they often referred to another DSM inattention item.