Doctors are just beginning to realize that there are many physical ills that can be related to sleep deprivation and sleep disorders. These happen mostly in adults as a result of being overweight, having some physical trauma or other cause, but they can occur in children. Sleep disorders are not a cause of either ADHD or autism, but they can definitely be a result of both of these conditions. People with ADHD have a hard time relaxing because they are trying to gain stimulation. Children with autism may experience anxiety or other symptoms that lessons the efficacy of sleep.