Preliminary evidence differentiating ADHD using brain SPECT imaging in older patients.

The objective of this study was to differentiate ADHD patients from a healthy comparison group using high resolution brain SPECT imaging in older patients. Using extensive chart reviews of structured interviews, DSM-IV criteria, and psychiatrist-given diagnoses, we identified 27 patients over age 50 with ADHD, either combined or inattentive types. Patients were compared to an age-matched group of healthy subjects with brain SPECT imaging at rest and during concentration using semiquantitative visual readings. Significantly lower cortical activity is noted in the ADHD group, particularly in the prefrontal poles, orbits, and parietal lobes. Older ADHD patients can be discerned from healthy subjects using brain SPECT. The results support the executive dysfunction model of ADHD.