In particular, PTPRD has been extensively associated with a large number of brain disorders (Uhl & Martinez, 2019), including attention‐deficit hyperactivity disorder (ADHD) (Anney et al, 2008; Elia et al, 2010; Distel et al, 2011; Jarick et al, 2014), restless leg syndrome (SNP study) (Schormair et al, 2008; Yang et al, 2011; Kim et al, 2013; Moore et al, 2014), addiction (Drgonova et al, 2015; Uhl et al, 2018), bipolar disorder (Malhotra et al, 2011), obsessive–compulsive disorder (Mattheisen et al, 2015), and intellectual disability (Choucair et al, 2015). This evidence concerns the gene PTPRD and bipolar disorder.