ACY-775 is a potent and selective HDAC6 inhbiitor. ACY-775 inhibits HDAC6 with low nanomolar potency and a selectivity of 60- to 1500-fold over class I HDACs. ACY-775 shares the antidepressant-like properties of other HDAC inhibitors, such as SAHA and MS-275, in the tail suspension test and social defeat paradigm