Described herein are neuroactive steroids of the Formula (I) : or a pharmaceutically acceptable salt thereof; wherein R1a and R1b are as defined herein. Such compounds are envisioned, in certain embodiments, to behave as GABA modulators. The present invention also provides pharmaceutical compositions comprising a compound of the present invention and methods of use and treatment, e.g., such for inducing sedation and/or anesthesia.