Light intervention plus CBT helps teens get more sleep

Combination light flash therapy and cognitive behavioral therapy enabled an earlier bedtime and increased sleep time by 43 minutes in teenagers, according to a randomized clinical trial published in JAMA Network Open.

“Using flashes of light is a powerful tool with which one can manipulate the circadian system, as it is more than 2- to 3-fold stronger than continuous light,” Katherine Kaplan, PhD, from the department of psychiatry and behavioral sciences, Stanford University, and colleagues wrote. “Thus, flash therapy delivered during the last hours of habitual sleep could set the human circadian pacemaker to an earlier hour, allowing teenagers to go to sleep earlier, and without the burden of having to wake earlier than usual.”

In a study comprising two phases, the investigators examined whether a novel intervention that used both light exposure during sleep and CBT could increase total sleep time in 102 high school students by helping them fall sleep earlier than usual. They measured diary-based sleep times, momentary ratings of evening sleepiness and subjective measures of sleepiness and sleep quality.

In the first phase, adolescents received either 3 weeks of light or sham therapy and were instructed to try to go to sleep earlier. In the second phase, adolescents received four 50-minute, motivation-focused CBT sessions once per week plus a modified light or sham therapy. Participants received light therapy every night during the 4-week intervention.

The light therapy entailed 3-millisecond light flash every 20 seconds during the final 3 hours of sleep (phase 1) or final 2 hours of sleep (phase 2), whereas sham therapy entailed using an identical device to deliver one minute of light pulses (in 20-second intervals) per hour during the final 3 hours of sleep (phase 1) or 2 hours of sleep (phase 2).

Overall, 72 participants were enrolled in phase 1 and 30 were enrolled in phase 2.

Although Kaplan and colleagues reported that light therapy alone did not result in a meaningful change in the timing of sleep, light therapy plus CBT moved sleep onset an average of about 50 minutes earlier and increased total sleep time by an average of about 43 minutes each night compared with sham therapy plus CBT.

In addition, light therapy plus CBT resulted in a 7-fold increase in bedtime compliance on average than that reported among teenagers who received sham plus CBT (2.21 vs. 0.29; P = .006).

The results also showed light plus CBT resulted in increased sleepiness during the evening during phase 2. Both groups saw reductions in daytime sleepiness and increases in sleep quality; however, parents reported greater reduction in their child’s sleep problems in the light plus CBT group (mean baseline vs. treatment end score = 18.3 vs. 14.3; P = .007).

“This type of passive light intervention in teenagers may lead to novel therapeutic applications,” Kaplan and colleague wrote. “Future studies should include objective measurements of sleep (eg, actigraphy), given the possibility of reporting bias, as well as long-term monitoring of the light intervention. This latter improvement would be an important next step to determine ongoing acceptance of the light therapy and to determine whether the beneficial effects of light plus CBT could be maintained for months or years.” – by Savannah Demko

Disclosure: Kaplan reports no relevant financial disclosures. Please see the study for all other author’ relevant financial disclosures.