Wash. Rev. Code § 48.44.245
For the purposes of RCW 48.44.240, "chemical dependency" means an illness characterized by a physiological or psychological dependency, or both, on a controlled substance regulated under chapter 69.50 RCW and/or alcoholic beverages. It is further characterized by a frequent or intense pattern of pathological use to the extent the user exhibits a loss of self-control over the amount and circumstances of use; develops symptoms of tolerance or physiological and/or psychological withdrawal if use of the controlled substance or alcoholic beverage is reduced or discontinued; and the user's health is substantially impaired or endangered or his or her social or economic function is substantially disrupted.
RCW 48.44.245
Effective date-Severability-1987 c 458: See notes following RCW 48.21.160.