A Clinically Useful Self-Report Measure of the DSM-5 MDD Anxious Distress Specifier

During the past 20 years, the clinical significance of co-existing anxiety disorders and anxiety symptoms in patients with major depressive disorder (MDD) has been increasingly recognized. The prevalence is high, with the majority of depressed patients having either symptoms of anxiety or a comorbid anxiety disorder. Anxiety in patients with MDD predicts greater morbidity than in those without anxiety. Co-occurring anxiety has been associated with increased suicidality, greater impairment in functioning, worse health-related quality of life, poorer longitudinal course, greater number of depressive episodes, and poorer response to treatment in controlled efficacy studies and uncontrolled effectiveness studies. Clinicians indicated that anxiety was the symptom that most commonly influenced their choice of antidepressant for patients with MDD.

To acknowledge the clinical significance of anxious features in depressed patients, DSM-5 included criteria for an anxious distress specifier for MDD. With increased attention likely to be given to anxious depression because of the addition of this specifier, it is important that rating scales be developed that measure symptoms of both depression and anxiety. The development of new scales is particularly timely in the context of recent recommendations to measure outcome during routine clinical practice. Measurement-based care has been emphasized in official treatment guidelines for depression, as well as in DSM-5. Self-report questionnaires are a cost-effective option to implement measurement-based care because they require little time to administer and correlate highly with clinician ratings.

In a recent report from the Rhode Island Methods to Improve Diagnostic Assessment and Services (MIDAS) project, my colleagues and I described a modification of a self-administered depression scale, the Clinically Useful Depression Outcome Scale (CUDOS), to include a 5-item subscale assessing the DSM-5 anxious distress specifier of MDD (CUDOS-A).

In a study of nearly 800 outpatients diagnosed with MDD, the CUDOS-A was found to be a reliable and valid measure of anxiety symptoms. The scale was more highly correlated with other self-report measures of anxiety than with measures of depression, substance use problems, eating disorders, and anger. The convergent and discriminant validity of the CUDOS-A was further supported by the finding that the measure was more highly correlated with clinician severity ratings of anxiety than of depression and irritability. In addition, CUDOS-A scores were significantly higher in depressed outpatients with anxiety disorders than in depressed outpatients without anxiety disorders. Consistent with other research on the high prevalence of anxiety in depressed patients, the majority of patients with MDD in our study met the DSM-5 anxious distress specifier on the CUDOS-A. Compared to patients who did not meet the DSM-5 specifier, the patients who did reported more functional impairment and poorer quality of life.

The CUDOS-A is the fourth in a series of “Clinically Useful” scales that were developed in the MIDAS project for use in clinical practice, with the other scales created to measure depression (CUDOS), anxiety (Clinically Useful Anxiety Outcome Scale [CUXOS]), and social anxiety (Clinically Useful Social Anxiety Disorder Outcome Scale). Each of the scales in the Clinically Useful series is intended to be brief, easily scored, and available to http://www.slaterpharmacy.com clinicians for personal use without cost. Each scale has the same rating instructions, which facilitates comparisons of symptom severity across varied symptom domains. The CUDOS and CUXOS are available for administration on the Internet on a free website that assists clinicians in monitoring the course of treatment (www.outcometracker.org).

Financial disclosure:Dr Zimmerman had no relevant personal financial relationships to report.