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In one study of 120 Dutch children ages 4 to 11 with GID 52% of the children diagnosed had one or more diagnoses in addition to GID. Thirty seven percent had anxiety disorders and 23% had behavioral disruptive disorders. (Wallien, M.S., et al. 2007, Psychiatric co-morbidity among children with gender identity disorder. J Am Acad Child Adolesc Psychiatry, 46:1307-14.) In another study 129 Dutch psychiatrists reported on 225 patients with GID. The report noted that 79% had personality disorders, 26% had mood disorders and 24% had psychotic disorders. (Campo J, et al. 2003. Psychiatric co-morbidity of Gender Identity Disorders: a survey among Dutch psychiatrists Am J Psychiatry. 160, 7:1332-6.)
http://www.childhealing.com/articles/genderidentitydisorder.php