A therapeutic drug for psychoneurotic disorders, which is useful for therapies of psychoneurotic disorders, especially restless legs syndrome is disclosed. The therapeutic drug for psychoneurotic disorders according to the present invention comprises as an effective ingredient an opioid κ receptor agonist compound (excluding pentazocine) such as (−)-17-(cyclopropylmethyl)-3,14β-dihydroxy-4,5α-epoxy-6β[N-methyl-trans-3-(3-furyl)acrylamide]morphinan hydrochloric acid salt.
