LAS VEGAS, Nov. 8 /PRNewswire/ -- ADDERALL XR(R) (mixed salts of a single- entity amphetamine product) significantly improved driving performance, cognitive function and attention in young adults with attention- deficit/hyperactivity disorder (ADHD) in a controlled driving simulator study conducted by the Washington Neuropsychological Institute and presented today at the 18th Annual U.S. Psychiatric & Mental Health Congress in Las Vegas, NV.
"Adolescent and adult patients often fail to appreciate the effect that ADHD symptoms such as inattention have on daily activities such as driving," said Gary Kay, Ph.D., president of the Washington Neuropsychological Institute. "Our study demonstrates that ADDERALL XR helps young adults improve their ability to drive and do so safely over a 12-hour period."
Accidents are the leading cause of death until age 40. A study by Barkley et al published in 2002 demonstrated that adults with ADHD had a significant higher incidence of traffic violations, and license suspensions than patients without ADHD. This research suggested that ADHD patients were five times more likely than non-ADHD patients to have five or more speeding tickets and three times more likely to have had three or more vehicular crashes. Because of this data, Kay felt it was important to study the effect that ADDERALL XR, a major ADHD therapy, has on driving performance in young adult patients with ADHD.
The Effect of ADDERALL XR Treatment on Driving Performance in Young Adults with ADHD
Patients with ADHD taking ADDERALL XR demonstrated significant improvement in driving safety and performance, as measured by a 2.5 point reduction in their average Driving Safety Score (DSS), compared to 2.5 point gain among those on placebo (P<.005). The investigators determined the participants' DSS from mean scores derived from safety-related driving parameters, including speeding tickets, traffic tickets, crashes, crash avoidance rating, time to collision and excess speed, as presented on the STISIM Drive(TM) Simulation System at both testing visits, weeks three and six.
Furthermore, ADDERALL XR significantly improved ADHD symptom control in young adults with ADHD as compared to those on placebo. Eighty percent of patients experienced at least a 30 percent reduction in their ADHD symptoms based on the ADHD Rating Scale (ADHD-RS) score when taking ADDERALL XR.
ADDERALL XR also had significant effects on the participants' attention, an important cognitive ability, as measured on the validated Kay Continuous Performance Test (KCPT), a 12-minute visual vigilance test that measures the ability to maintain attention during a monotonous, repetitive task.
For example, participants treated with ADDERALL XR had significantly improved reaction time and significantly fewer lapses in attention compared to those receiving placebo. There was a particular advantage for those patients who received ADDERALL XR at the first test visit. Their performance was normal on this test of vigilance. In contrast, those who had received placebo at the first visit performed in the deficient range. At the second test visit, those individuals who had been taking ADDERALL XR at the time of the first visit were now taking placebo. Their performance on the vigilance test declined, though not to the deficient level of individuals who had been taking placebo at the first visit. As expected, those individuals taking ADDERALL XR at the second visit performed normally on the vigilance test. These findings suggest that there is a carryover beneficial effect of having performed a mentally demanding task in a competent and effective state that is still evident when the individual is not taking the medication.
About the Study
During the six-week study period, investigators randomized 15 patients to receive an initial three weeks of treatment with ADDERALL XR or a placebo, but neither investigators nor participants knew to which group they were assigned until the end of the study. At the end of this period, investigators switched the group taking ADDERALL XR to receive three weeks of placebo treatment, while the group taking a placebo crossed over to receive three weeks of ADDERALL XR. All participants were diagnosed with ADHD using the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR(R)) criteria. Participants received doses of ADDERALL XR at 20 milligrams (mg) for the first week and then increased to 40 mg and 50 mg for the second and third weeks, respectively.
Following a screening period, investigators tested all patients on the driving simulator at a practice visit (testing visit one) and after each three-week treatment period (testing visits two and three). Investigators measured driving performance at two, seven and 12 hours after participants took medication. The STISIM, a validated system, assesses critical driving skills, including situation awareness, hazard perception, risk assessment and decision-making under time pressure.
The majority of side effects during the trial were mild or moderate and consistent with known side effects of stimulant medications. The most common side effects reported by patients taking ADDERALL XR during the trial included decreased appetite, weight loss, dry mouth, insomnia and bruxism (teeth grinding). The most common side effects reported by patients taking placebo during the trial included decreased weight and headache.
The study was supported by Shire.
About Washington Neuropsychological Institute
The Washington Neuropsychological Institute (WNImail@aol.com) is a private, independent research organization that conducts clinical research trials and provides consulting services to government agencies and to the pharmaceutical industry. At their Northwest Washington, DC facility WNI has conducted studies on antihistamines, anticholinergics, memory enhancement drugs, jet lag remedies, head trauma, epilepsy, diabetes, Parkinson's Disease, Alzheimer's Disease, and ADHD. WNI is fully equipped to support Phase III and Phase IV clinical trials. The institute specializes in computer-based neurocognitive testing and driving simulation. In addition, professional staff members are frequent lecturers at national and international medical and scientific meetings.
ADHD affects approximately 7.8 percent of all school-age children, about 4.4 million U.S. children aged 4 to 17 years, according to the U.S. Centers for Disease Control and Prevention. Up to 80 percent of children with ADHD may continue to experience symptoms into adolescence and up to 65 percent may continue to experience symptoms into adulthood. Approximately eight million American adults currently struggle with the inattention, impulsivity and hyperactivity symptoms of ADHD. Without an effective treatment program, ADHD may have serious adverse effects on the lives of those affected. The disorder frequently results in poor performance at school and in the workplace, while social and family relationships also may suffer. Evidence suggests that many with untreated ADHD may be at risk for other problems, including poor performance in the workplace and poor self-image.
ADHD is a neurological behavioral disorder that manifests as a persistent pattern of inattention and/or hyperactivity-impulsivity that is more frequent and severe than typically observed in individuals at a comparable age and maturity level. Because everyone shows signs of these behaviors at times, the behaviors must appear early in life (before age 7) and continue for at least six months, according to the ADHD diagnosis criteria as defined in the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR(R)).
Although there is no cure for ADHD, physicians and advocates are finding ways to help people with the condition learn to adapt to their school, home, social and work settings. ADHD usually can be successfully managed with a combination of treatments, such as behavioral therapy, skill building and medication. Medication should be considered part of an overall multi-modal treatment plan for ADHD.
About ADDERALL XR
ADDERALL XR(R) was generally well tolerated in clinical studies. The most common side effects in studies included: children -- decreased appetite, difficulty falling asleep, stomachache, and emotional lability; adolescents -- loss of appetite, difficulty falling asleep, stomachache, and weight loss; adults -- dry mouth, loss of appetite, difficulty falling asleep, headache, and weight loss.
Patients should speak with their doctor if they have a history of high blood pressure or any heart conditions, glaucoma, thyroid problems, emotional instability, mental illness, or a known allergy to this type of medication. Abuse of amphetamines may lead to dependence. Misuse of amphetamine may cause sudden death and serious cardiovascular adverse events. These events have also been reported rarely with amphetamine use.
If you are currently taking or have recently taken a type of antidepressant called a MAO inhibitor or have a pre-existing structural heart abnormality, you should not take Adderall XR. There is a potential for worsening of motion or verbal tics and Tourette's syndrome. A patient should report any new psychological symptoms to his or her physician.
Poster # 241, Tuesday, November 8, 2005, 3:45 PM PST
"The Effect of Adderall XR and Atomoxetine on Simulated Driving Safety in Young Adults with ADHD." Kay, Gary, Ph.D.
Washington Neuropsychological Institute