Retail-Grade Weighted Blanket Effectiveness on ADHD-related Sleep Disturbances (BEAD)

The goal of this clinical trial is to investigate if a commercially available (retail-grade) weighted blanket can improve sleep in children with Attention Deficit Hyperactivity Disorder (ADHD) and sleep disturbances. 100 children will be enrolled in the study. The location of the intervention is at Frederiksberg Hospital and Odense University Hospital in Denmark. The main objectives are: * Does using a retail-grade weighted blanket increase total sleep time (TST)? * Does it help children fall asleep faster, wake up fewer times at night, and sleep more efficiently overall? * Does better sleep relate to changes in daily functioning, ADHD symptoms, parental stress, and child well-being? * Do adverse events occur while children use retail-grade weighted blankets? This is a single-group, open-label study. All participants receive a weighted blanket, and researchers compare each child's sleep before and after the 4-week blanket intervention period. Who can take part: Children aged 5 to 12 years who have a confirmed ADHD diagnosis, and also experience sleep disturbances. Children must have completed a usual-care sleep hygiene program within the last 6 months. if they use ADHD medicine or sleep medication the dosage must be stable for at least two weeks before enrolling. Children who used any type of weighted blanket within the last three months, or have health conditions that make blanket use unsafe, cannot take part in the trial. What will happen: Participation lasts about seven weeks, including measurements before and during the weighted blanket intervention period. Participants will: * Attend a baseline visit (in person or online) where a caregiver gives consent and receives instructions. * Wear a small sleep monitor (actigraphy) on the non-dominant wrist for 1 week before starting the blanket * Attend an intervention visit to try the weighted blanket options and choose the most fitting weighted blanket for their sensory needs. * Use the weighted blanket every n