MCHR1 and bipolar disorder: The first genetic evidence that an association might exist between the MCH system and schizophrenia was published in 2006 by Severinsen et al. [62], showing an association between MCHR1 (previously known as GPR24) and schizophrenia plus bipolar disorder in the isolated Faroe Island population, with a less robust finding for alleles in their study subjects from mainland Scotland.