SORCS2 and attention deficit-hyperactivity disorder: Although SorCS2 is known to play a crucial role in neuronal viability and function (Glerup et al., 2016), human epidemiological studies have reported that single nucleotide polymorphisms in SorCS2 are associated with the risk of developing psychiatric disorders such as ADHD (Alemany et al., 2015), bipolar disorder (Baum et al., 2008; Ollila et al., 2009), and schizophrenia (Christoforou et al., 2011).