NH HB1790

Expands the definition of "mental illness" for involuntary admission purposes to include impairment primarily caused by substance use disorder, allowing individuals with severe substance use disorders to be involuntarily admitted to treatment facilities

Defines "substance use disorder" as chronic consumption of controlled substances or inhalation of toxic vapors that substantially injures a person's health, interferes with social/economic functioning, or results in loss of self-control over substance use

Applies the expanded definition to both emergency involuntary admissions (RSA 135-C:27) and non-emergency involuntary admissions (RSA 135-C:34)

Explicitly excludes from the expanded mental illness definition: epilepsy, intellectual disability, alcohol intoxication, and alcohol dependence or addiction

Takes effect January 1, 2027