FGFR1 and major depressive disorder: The raphe 5-HT1A autoreceptor when being part of the FGFR1-5-HT1A heteroreceptor complexes may have a beneficial role in depression by assisting in the recovery of 5-HT nerve cell trophism including 5-HT synthesis and storage (Fuxe et al., 2014; Borroto-Escuela et al., 2016b).