....A significant association between Hg exposure from thimerosal-containing childhood vaccines and a diagnosis of tic disorder (TD) has now been found in six epidemiological studies(Verstraeten et al. 2003, Andrews et al. 2004, Thompson et al. 2007, Young et al, 2008, Barile et al. 2012, Geier et al. 2015). The Thompson study states that, “The replication of the findings regarding tics suggests the potential need for further studies.”