This is not a new decision but worth re-reading.
"Chronic pain syndrome and related medical conditions have emerged in recent years as one of the most difficult problems facing Workers' Compensation schemes in Canada and around the world. There is no authoritative definition of chronic pain. It is, however, generally considered to be pain that persists beyond the normal healing time for the underlying injury or is disproportionate to such injury, and whose existence is not supported by objective findings at the site of the injury under current medical techniques. Despite this lack of objective findings, there is no doubt that chronic pain patients are suffering and in distress, and that the disability they experience is real. While there is at this time no clear explanation for chronic pain, recent work on the nervous system suggests that it may result from pathological changes in the nervous mechanisms that result in pain continuing and non-painful stimuli being perceived as painful. These changes, it is believed, may be precipitated by peripheral events, such as an accident, but may persist well beyond the normal recovery time for the precipitating event. Despite this reality, since chronic pain sufferers are impaired by a condition that cannot be supported by objective findings, they have been subjected to persistent suspicions of malingering on the part of employers, compensation officials and even physicians." (underlining added)
Nova Scotia (Workers' Compensation Board) v. Martin,  2 S.C.R. 504 at para. 1 (Gonthier J.).