Psychiatric co-morbidity in adolescents is common, with the majority of those who have depression also having at least one anxiety disorder, and many meeting the diagnostic criteria for more than one anxiety disorder. In our recent paper published in this journal, we reported that approximately one in three adolescents with Chronic Fatigue Syndrome (CFS/ME) has either an anxiety disorder, or major depressive disorder, or both.

In clinical practice, screening questionnaires which ask about depression and anxiety symptoms, such as the Revised Children’s Anxiety and Depression Scale, RCADS, and the Hospital Anxiety and Depression Scale, HADS, are often used as part of the assessment process. However, in our paper, we reported our findings of variable discriminative validity of these questionnaires for detecting anxiety and depression separately. Whilst we found sufficiently accurate threshold scores for classifying those with anxiety disorders on both the 47-item and 25-item parent and child versions of the RCADS, we could not identify a sufficiently accurate threshold score for classifying those with depression. We also could not identify sufficiently accurate threshold scores on the HADS for either anxiety or depression.

Clinicians treating children with health disorders need a simple screening mechanism to identify those with co-morbid mental health problems that will require further assessment. Using one threshold score is therefore arguably more useful than calculating two separate scores (for depression and anxiety). Given the high co-morbidity between depression and anxiety in this population, we sought to identify the threshold score for mental health problems on two commonly used screening questionnaires, the RCADS-total and the HADS-total…

A total of 164 participants, mean age 15, mostly female (70%) completed the HADS and a subsample of 89 (54%) completed the RCADS. The subsample did not differ significantly on fatigue, physical functioning, HADS total, or age (data not shown)…

For identifying co-morbid mental health problems (anxiety and/or depression), we found that both the full 47-item version and the brief 25-item version of the RCADS were sufficiently accurate and could identify threshold scores deemed to be suitably sensitive and specific to be useful for screening in a clinical setting…

Participants were recruited from specialist services, so findings may not generalise to other settings, nor to those who were too severely affected to participate. The diagnostic interview was also assumed to be completely accurate, and whilst we made every attempt to ensure that it was robustly conducted, diagnostic judgements may mean that errors were made. Nonetheless, our findings suggest that a total cut-off score of ≥ 27 on the 25-item RCADS offers a simple way of identifying children with CFS/ME with co-morbid anxiety and depression.