Light Therapy Holds Promise for Treating Symptoms of Adult ADHD

For Immediate Release - October 27, 2006 – (Toronto) - The clocks go back Sunday, giving us more hours of darkness. For many this is a minor disruption. But, for many others, including those thousands of Canadians living with adult attention-deficit/hyperactivity (ADHD) disorder, this time change can have more serious effects on daily living. A new study from the Centre for Addiction and Mental Health (CAMH) suggests that light therapy, during the fall and winter months, may be a useful supplementary treatment for adults with ADHD. This study is the first evaluation of light therapy in adults with ADHD.

Many adults with ADHD have a delayed sleep/activity rhythm. Some are also prone to symptoms of Seasonal Affective Disorder (SAD), a subtype of depression occurring in the fall/winter months. In either case, the associated symptoms of fatigue and poor concentration can be especially disabling for adults with ADHD, particularly in the early part of the day. This study, led by Dr. Yuri Rybak, University of Western Ontario, and Dr. Robert Levitan, a clinical researcher at CAMH, investigated the effectiveness of morning bright light therapy as a focused strategy to counteract these problems.

The study demonstrated that participants exposed to thirty minutes of light therapy, using a full-spectrum fluorescent light box that filtered out ultraviolet wavelengths, had a significant decrease in core ADHD symptoms such as inattention, difficulty sustaining effort, impulsive responding to stimuli, and hypo-arousal/fatigue.

Said Dr. Rybak, “the study showed that 55% of participants had a marked improvement on depression scores, meaning they experienced fewer symptoms of depression. Also, approximately 28% of had a full or partial improvement in attention deficit symptoms, measured with both questionnaires and actual laboratory-based tasks. These are very promising results.”

Strikingly, the strongest predictor of improvement in ADHD symptoms resulted from a change in circadian activity rhythms rather than decreasing the symptoms of SAD that are often experienced by adults with ADHD. The scientists suggest that light therapy may correct a core deficit in the basic arousal mechanism in adults with ADHD, as well as change circadian rhythms.

“It looks like many adults with ADHD have a phase delay in their circadian activity rhythms. This causes them to go to sleep late and have great difficulty getting going in the morning. This makes them very much out of sync with typical social and work demands,” said CAMH’s Dr. Levitan. “The light therapy gave participants more energy, they were able to wake up and go to sleep earlier, and this allowed them to begin to return to more conventional schedules.”

These results suggest that light therapy may have important clinical benefits beyond the treatment of conditions such as SAD. Further studies are needed in this complex and still evolving area of research.

The Centre for Addiction and Mental Health (CAMH) is one of the largest addiction and mental health organizations in North America and Canada's leading mental health and addiction teaching hospital. CAMH is a Pan American Health Organization and World Health Organization Collaborating Centre, and is fully affiliated with the University of Toronto. CAMH combines clinical care, research, policy, education and health promotion to improve the lives of people impacted by mental health and addiction issues.

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For more information or to schedule interviews with Dr. Robert Levitan, please contact Michael Torres, Media Relations Coordinators at (416) 595-6015 or Leah Young, Manger, Research Communications, CAMH at (416) 535-8501 x 4932.