Quantifying mental and behavioural impairments in the context of catastrophic impairment analysis.

This article explores the quantification of mental and behavioural impairment in the context of catastrophic impairment as defined by the Ontario Statutory Accident Benefit Schedule (the "SABS"). It reviews the relevant areas of the SABS, along with key arbitrations, appeals and court rulings relevant to the issue of quantifying mental and behavioural impairments, as well as a psychological perspective on this issue. The SABS mandates use of the 4th edition, 1993, of the AMA Guides to the Evaluation of Permanent Impairment (the "AMA Guides"). This article outlines approaches taken in various editions of the AMA Guides, with a particular focus on the2nd, 4th and 6th editions. It also offers explanations of the approaches taken by Worker Safety Insurance Bureau of Ontario, Colorado Division of Workers' Compensation, and the State of California Division of Workers' Compensation. This article analyzes the merits and shortcomings of each of these approaches from a psychological perspective.