In adolescents and young adults, delayed sleep-wake phase disorder (DSWPD) may be associated with attention-deficit/hyperactivity disorder (ADHD) and restless legs syndrome (RLS), which can make falling asleep difficult and worsen insomnia. At The Sleep Congress 2025 in Strasbourg, France, a presentation reviewed the screening and management strategies for these closely linked disorders.

“DSWPD, RLS, and ADHD share common neurobiological, genetic, and clinical mechanisms and exacerbate one another,” said Sylvie Royant-Parola, MD, a Paris-based psychiatrist specializing in sleep medicine, during her presentation. The combination of these three conditions forms a “vicious trio,” worsening difficulty falling asleep and DSWPD. “The disruption is then at its peak.”

“Delayed sleep-wake phase disorder leads to sleep deprivation, which can contribute to the development of depression. This can worsen restless legs syndrome or even trigger it if treatment with antidepressants is initiated. All of these factors affect ADHD. Together, these factors contribute to sleepiness, fatigue, and poorer academic performance.”

Assessing Iron Status and ADHD

In this context, diagnosis is even more complex because “symptoms overlap,” the sleep psychiatrist added. “Their coexistence complicates management…and justifies multidimensional screening, including assessment of iron status,” with iron deficiency being the main cause of RLS. Treatment is “individualized and comprehensive.”

DSWPD is defined as a chronic shift in sleep onset and wake times, delayed by several hours. When constrained by early morning wake times, individuals with this circadian rhythm disorder accumulate sleep debt, leading to sleepiness, learning difficulties, and affective disorders.

During adolescence, pubertal hormonal changes and increased sensitivity to nighttime light are cited as potential causes of the slowing of the biological clock associated with DSWPD. The condition may also be favored by changes in behavioral habits, such as increased screen exposure and social outings. Nearly 1 in 5 adolescents are affected.

Adolescents are more frequently affected by ADHD that is particularly common among those who develop DSWPD. “ADHD affects about 5% of adolescents. It is also present in 26% of adolescents and young adults with DSWPD,” as Royant-Parola noted. Moreover, “ADHD is more severe in cases of phase delay.”

ADHD generally persists from childhood to adolescence. It is associated with attention difficulties, hyperactivity, and/or impulsiveness that are inappropriate for age, with a significant impact on daily life. Motor hyperactivity is reduced in adolescents. This disorder is associated with an increased risk for academic failure, anxiety, and risky behaviors.

Encourage Physical Activity

In addition to DSWPD, ADHD in adolescents is also frequently linked to RLS, suggesting “shared pathophysiological mechanisms.” As a result, “any adolescent with ADHD and/or RLS who complain of sleep problems should undergo systematic screening for associated disorders,” Royant-Parola said.

Obstructive sleep apnea syndrome (OSAS) may also be investigated, but “only in the presence of suggestive symptoms,” such as snoring and breathing pauses. “To date, no study has shown an increased prevalence of OSAS in adolescents with DSWPD,” she added, noting that the mechanisms involved are distinct.

For DSWPD management, a chronobiological approach using synchronizers is recommended, particularly for exposure to morning daylight. Light therapy involves exposure to white light that simulates daylight for a set duration to correct phase delay.

Daily physical activity is also recommended to avoid exercising in the evening before bedtime. “In adolescents, the best time to train depends on chronotype.” For most adolescents with DSWPD, the optimal window is between 1 PM and 3 PM, which is favorable for falling asleep in the evening.

Multidisciplinary, Multimodal Care

The overall management is multidisciplinary and multimodal, involving chronotherapy, behavioral interventions, and — when necessary — psychological and psychiatric support. In particular, evening screen time should not exceed 2 hours, and exposure should stop 1 hour before bedtime.

In cases of RLS, management first relies on correcting the iron deficiency. This syndrome remains poorly understood and is often associated with disturbances in iron regulation. According to the recommendations, iron supplementation is advised when ferritin is < 75 µg/L. Aggravating factors such as caffeine intake, alcohol consumption, and smoking should be avoided.

In mild forms of RLS, behavioral changes alone may be sufficient to alleviate symptoms. Going to bed and waking up at fixed times are among the recommendations, along with regular daytime physical activity and stretching exercises before bedtime.

In the presence of ADHD, behavioral treatment is again the preferred first-line approach to improve sleep before pharmacologic therapy, with the establishment of routines that include avoiding screens before bedtime. In cases of persistent symptoms, anxiolytic hydroxyzine (Atarax) and alimemazine (Théralène) may be prescribed to improve sleep.

“Sleep disorders are a major risk factor for depression, so joint management with a psychiatrist is also necessary,” Royant-Parola said. “The link between DSWPD and depression is extremely strong.” Sleep deprivation is considered “a warning sign of suicide attempt,” she emphasized.

This story was translated from Medscape’s French edition.