Since the cyclothymic temperament may be of more relevance to BDII, we should not expect this temperament to perform as well in our sample of BDI subjects. Interestingly, though, the best association for the cyclothymic temperament was observed for the SLTRIK1 gene region on chromosome 13q31 with several p values <10−5. The 13q31 region has been implicated previously in a linkage study of BD families segregating psychotic symptoms (44), and linkage to the nearby 13q32 region has been observed for BD (45–47). Associations to SLITRK1, which functions in neurodevelopment, have also been reported for Tourette’s Syndrome (48).
