Conflict of interest: None declared.
Letter to Editor
Article first published online: 4 MAR 2013
Copyright © 2013 Wiley Periodicals, Inc.
American Journal of Medical Genetics Part B: Neuropsychiatric Genetics
Volume 162, Issue 3, page 294, April 2013
How to Cite
Kawada, T. (2013), Actigraphic evaluation for patients with attention deficit/hyperactivity disorder. Am. J. Med. Genet., 162: 294. doi: 10.1002/ajmg.b.32140
How to Cite this Article: Kawada T. 2013. Actigraphic Evaluation for Patients With Attention Deficit/Hyperactivity Disorder. Am J Med Genet Part B 162B:294–294.
- Issue published online: 19 MAR 2013
- Article first published online: 4 MAR 2013
- Manuscript Accepted: 29 JAN 2013
- Manuscript Received: 8 JAN 2013
Labbe et al.  examined the effect of methylphenidate in patients with attention deficit/hyperactivity disorder with special reference to the latrophilin 3 genes. They used accelerometer, named Actiwatch® (Mini-Mitter Co., Bend, OR), to monitor objective and quantitative wrist movement. Although the study design and evaluation method are valid and appropriate, there is a caution on their use of Actiwatch®.
The sampling frequency of the Actiwatch® was set at 32 Hz and the sensitivity at 0.05 g. They selected 15 sec interval as one epoch, and the number of body movements was calculated by summing the activity count. As a standard procedure, sleep/wake judgment was then made by using simple algorithm, which was also prepared as software named Actiware®. Different from the standard method, they used original activity count for the analysis. I suppose that many machines were required for their study, and the activity count from different Actiwatch® might be used for the analysis. I previously described the limitation for monitoring wrist movement by Actiwatch® [Kawada, 2012]. In this article, I quoted user's manual of Actiwatch®, in which the absolute value of activity count from different Actiwach® does not always agree with each other. Two-dimensional sensors are made precisely, and mounting and positioning affect raw data from Actiwach®.
I recommend conducting validation study for the direct use of activity count from Actiwatch® for the clinical evaluation. Although they tried to remove the placebo effect, reliability of activity count from the same machine and inter-machine variation are required to keep validation of their study.
- 2012. The handling of absolute values of activity counts by actigraphy. J Neurol Sci 312(1–2):194. .
- 2012. Refining psychiatric phenotypes for response to treatment: Contribution of LPHN3 in ADHD. Am J Med Genet B Neuropsychiatr Genet 159B(7):776–785. , , , , , , .