A medical device includes an elongate body having a proximal end and a deflectable distal region, a handle coupled to the proximal end, an actuator movable relative to the handle, and a resistance assembly adjacent the actuator. The resistance assembly exerts a force on the actuator that varies according to a direction in which the actuator is moving relative to the handle. For example, the resistance assembly can exert a lower (or zero) force when the actuator is moving relative to the handle in a direction that effects deflection of the distal region of the elongate body from neutral and higher when the actuator is moving relative to the handle in a direction that effects return of the distal region of the elongate body towards neutral. The resistance assembly can also include materials that exhibit anisotropic frictional properties and/or have surface finishes or treatments that yield directionally-dependent frictional forces.