Abstract: Disclosed herein are substituted phenyl compounds of formula I as defined herein that may be utilized as inhibitors of the interaction between the subunits of hyperpolarization-activated cyclic-nucleotide gated (HCN) channels, such as HCN1, and an auxiliary subunit of HCN channels which is the tetratricopeptide repeat-containing Rab8b-interacting protein (TRIP8b). The disclosed compounds may be used in pharmaceutical compositions and methods for treating neurological diseases and disorders such as depression, and in particular Major Depressive Disorder (MDD).