I’ve hinted at this implication of the mental-burden-as-suffering model in previous posts about mental illness and quality of life, but I should make it explicit: in this paradigm, all illness is mental illness.
The physical-versus-mental dichotomy is a false one. Physical pain, on its own, is not the same as suffering, as lovers of spicy food will attest. The mental distress—whether from physical pain or discomfort, or mental illness, or threatening or even awkward social situations—is the suffering.
Physical conditions are simply mental conditions with a physical component. Hell, even mental illnesses like depression have well-documented physical symptoms. The approach to reducing suffering due to all health conditions, physical or mental, should be the same as reducing any kind of mental burden.