This is illustrated in Supplementary Table S1, which presents the methods and results of the ten original articles reporting 11 studies, identified at PubMed in October 15th, 2018 using the key words “COMT” AND “anxiety” AND “child.” Fourteen out the 24 articles retrieved were excluded, because they were review articles, or did not investigate human subjects, did not focus on children, did not have comparison groups, or focused on psychotic and obsessive-compulsive disorder symptoms. Here, COMT is linked to Anxiety.