COMPUTERIZED ADD/ADHD SCREENING

Larry D. Rosen, Ph.D.

The National Psychologist

March/April 2001


Five and a half years ago I wrote one of my first National Psychologist columns touting the value and power of new computerized ADD/ADHD detection tools. This past month I have been reviewing updated versions of these instruments plus gathering information on other computerized ADD/ADHD detection programs.

Recent reports indicate that 5% of school age children and 3% of adults suffer from ADD or ADHD. Primary symptoms include attention, impulsivity and activity. Two types of tests are typically used to detect ADD/ADHD. Both require the client to watch a display on the screen or listen to sounds and detect the difference between targets and non-targets. When a target is heard or seen, a reaction must be made. Infrequent targets test attention or vigilance while frequent targets test impulsivity and inhibition.

These tools help clinicians support hypotheses about the existence of ADD/ADHD. They also caution the user that other tools must be used to make a complete decision. With repeated administrations, either measure can be used to monitor the effects of medication.

Most of these programs are tests of continuous performance that require the patient to press a button when a target figure is presented. The tests examine response time and errors of both omission (failing to respond to a target) and commission
(responding when there is no target.

Conners' Continuous Performance Test II (CPT-II).

The CPT-II requires the client to press the space bar or click the mouse button when he or she sees any letter "other than an X" in the middle of the screen. It is a Windows-based program that is easy to install. From start to finish, I was up and running in less than 10 minutes. The Quick Start Guide was very helpful and the manual was both comprehensive and instructive.

The CPT-II requires no additional hardware other than a Pentium processor; 32 MB of RAM (64 recommended) and 120 MB of available hard drive space. The CPT-II is part of Psych Manager Lite with many other programs available from MHS (1-800-456 3003).

The CPT-II includes a short practice test to make sure that the client understands the instructions and a test that lasts 14 minutes. The test presents targets and non-targets at three different time intervals - 1 second, 2 seconds and 4 seconds - each presented six times for a total of 18 blocks. Each block includes two targets and 18 non-targets for a total of 324 non-targets and 36 targets.

The CPT-II also includes a normative sample of 2,686 clinical and nonclinical subjects. Each client is compared to both normative samples to determine how scores are either the same or different from the norms. Differences are measured in T-Scores and are labeled markedly, moderately or mildly atypical, within the average range, and good or very good performance. The number of atypical ratings and their specific meanings build the CPT-II's case for attentional disorders.

The CPT-II has included a new confidence index that is the percentage out of 100 clients that would be correctly classified based on a profile. In addition, the CPT-II provides an overall index, which is very useful for combining all CPT scales into one measure.

MHS is a large organization with many products other than the CPT-II. Support is provided by a staff of 4 between the hours of 9 AM and 5 PM EST or via e-mail. MHS's support is on a triage system. If your problem is judged as an easy one (only taking a few minutes), the support tech will try to answer it at that time. If your problem is seen as lengthy, the support tech will schedule an appointment. Voice mail messages are returned within 24 hours.

The CPT-II is designed for clients ages 6 years and older. For younger clients (4 and 5 years old), MHS has a Conners' Kiddie CPT. The CPT-II costs $495 for unlimited usage.

My one and only problem with the CPT-II came when I finished the 14-minute testing and could not figure out how to end the program and view the report. It wasn't in the Quick Start Guide and I finally found it in the manual on Page 118.

Tests of Variables of Attention Continuous Performance Test (TOVA)

The TOVA is a DOS-based program that measures both auditory and visual attention. The auditory attention test plays high and low tones at the same rate for 22.5 minutes. The longer testing time was selected on purpose to identify clients who can attend and compensate for short periods of time.

If you are going to use the auditory test, the TOVA comes with all the equipment, including speakers, to connect to your computer.

The visual test is also 22.5 minutes and uses symbols instead of letters to control for language issues. The first half of both tests present rare targets, intended to lull the client into a bored state and see how he/she reacts. The second half presents rare non-targets. All are presented at the same rate.

The TOVA includes a short setup guide plus three manuals - clinical, professional and user. Each manual is well written and useful.

The TOVA presents much of the same information as the CPT-II in a similar reporting format. One interesting difference is that the CPT-II simply prints one total report while the TOVA has six different parts of the report, each printed separately.

The auditory TOVA was normed on 2,500+ children from 6 to 19, while the visual TOVA was normed on 1600+ children and adults ranging from 4 to 80+ years old.

The TOVA is distributed by Universal Attention Disorders (800-729-2886) and is its sole product. There are two fulltime support technicians to help you with your problems. After I hooked up the auditory equipment to my laptop I could not get any sound so I called and spoke with Josh who fixed the problem in 10 minutes.

The TOVA uses a microswitch that you attach to the back of your laptop or tower. In research done in 1995, the TOVA group found that the accuracy of this microswitch was accurate to1 msec (1/1000th of a second) while keyboard key presses or mouse clicks were only accurate to 28 msec. Since both reports made the same statement about my attentional disorders, this was not critical in my case. But if this level of accuracy is important to you, this may be a critical factor.

The TOVA costs $395 for the first five administrations and $15 per additional test. There is also a Home TOVA that costs about $10 for each administration and interpretation.

Three other tests will be reviewed in the next issue. Stay tuned!

Copyright, 2001, The National Psychologist. Reprinted with permission. The National Psychologist is a privately-owned bimonthly newspaper which may be purchased for $30 a year. Write or call: TNP, 6100 Channingway Blvd., Suite 303, Columbus, OH 43232; telephone: 614.861.1999 or fax with Visa or MC to 614.861.1996.