- The prevalence of mental health problems in children 1(1/2) years of age - the Copenhagen Child Cohort 2000. Skovgaard, A.M., Houmann, T., Christiansen, E., Landorph, S., Jørgensen, T., Olsen, E.M., Heering, K., Kaas-Nielsen, S., Samberg, V., Lichtenberg, A. Journal of child psychology and psychiatry, and allied disciplines (2007)