DSPD is also genetically linked to ADHD by findings of polymorphism in genes in common between those apparently involved in ADHD and those involved in the circadian rhythm


[1][2]

and a high proportion of DSPD among those with ADHD.

[3]

  1. ^ Kissling C, Retz W, Wiemann S, Coogan AN, Clement RM, Hünnerkopf R, Conner AC, Freitag CM, Rösler M, Thome J. A polymorphism at the 3′-untranslated region of the CLOCK gene is associated with adult attention-deficit hyperactivity disorder. American Journal of Medical Genetics Part B: Neuropsychiatric Genetics. 5 April 2008, 147B (3): 333–338. doi:10.1002/ajmg.b.30602. 
  2. ^ Baird AL, Coogan AN, Siddiqui A, Donev RM, Thome J. Adult attention-deficit hyperactivity disorder is associated with alterations in circadian rhythms at the behavioural, endocrine and molecular levels. Molecular Psychiatry. October 2012, 17 (10): 988–995. PMID 22105622. doi:10.1038/mp.2011.149. 
  3. ^ Van der Heijden KB, Smits MG, Van Someren EJ, Gunning WB. Idiopathic chronic sleep onset insomnia in attention-deficit/hyperactivity disorder: a circadian rhythm sleep disorder. Chronobiology International. 2005, 22 (3): 559–570. PMID 16076654. doi:10.1081/CBI-200062410.