According to the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), motivation is a need or desire that causes a person to act and may be a key factor in an individual's physical or mental impairment. Poor motivation can cause poor functioning, and personality characteristics and underlying character are important determinants of an individual's motivation to benefit from rehabilitation. Particularly because of the subjective and highly sensitive nature of most mental and behavioral disorders, examinees have multiple self-interests, and, when one party engages in activities that are inconsistent with the other's expectations, resolution may depend on the employee's and employer's shared perceptions that the return to work is positive and consistent with each party's self-interests, particularly if both believe this step will succeed. Participants are motivated by the real or imagined costs associated with the return to work, and examinees may have concerns about facing coworkers, losing benefits or wages, dealing with labor relations, or simply making a change. When determining an individual's degree of motivation to return to work, the physician should consider the following: the value or usefulness of returning to work; employer's and employee's perceptions of the potential for successful return to work; and the real and perceived costs of work return (functional renewal) for the individual.