The WHODAS 2.0 possesses strong psychometric properties and provides a global disability score as well as six domain scores: cognition, mobility, self-care, getting along with others, participation in society, and life activities. However, several challenges emerge in attempting to use WHODAS 2.0 scores—particularly the self-report version—as a one-size-fits-all metric of functional disability associated with mental disorders. First, the WHODAS 2.0 was developed as a measure of disability associated with all physical and mental disorders. As such, many items are not relevant for assessing disability related to mental disorders. Second, there are no established thresholds for interpreting the global or domain-specific scores in relation to the criterion of clinically significant impairment. Moreover, it is unclear whether any cutoff score would be meaningful across patients with different types of mental disorders, let alone for patients with any kind of disease or disorder and across all demographic categories. Third, the instructions for the WHODAS 2.0 require respondents to make attributions about the source of their disability. These attributions may be inaccurate, particularly in the context of co-occurring disorders. A fourth difficulty emerges when interpreting scores on the life activities domain, which comprises household and work/school activities. When completing this scale, people who are neither working nor in school are instructed to skip these items. Therefore, this key aspect of disability is not reflected in the disability scores for people who are not working because of functional disability. Paradoxically, someone who is working despite some level of disability in this domain will complete these items and receive a higher disability score. Finally, when assessing someone who is socially withdrawn as a result of a mental disorder, the respondent may, because of his or her isolation, report little or no difficulty in social functioning. Thus, scores on the WHODAS 2.0 must be contextualized to be interpretable.