The prevalence of Sleep-Related Rhythmic Movement Disorder (RMD) is highest in infants and children, and declines with age.84
Children who experience environmental stressors and those with developmental or intellectual developmental disorders (e.g., autism) have higher rates of RMD.85 Most children without such disorders spontaneously outgrow RMD, but rare cases are found in apparently normal adolescents and adults.86
84 Thorpy M, “Classification of Sleep Disorders,” in Kryger M, Roth T, Dement W (ed.), Principles and Practice of Sleep Medicine (5th Edition), St. Louis: Elsevier Saunders, 2011, pages 680 - 693.
85 Hoban TF. Rhythmic movement disorder in children. CNS Spectr. 2003;8:135-138.
86 Anderson KN, Smith IE, Shneerson JM. Rhythmic movement disorder (head banging) in an adult during rapid eye movement sleep. MovDisord. 2006;21:866-867.