Cognitive behavioral therapy for childhood anxiety disorders: What happens to comorbid mood and behavioral disorders? A systematic review

Highlights

• CBT focused on the primary anxiety disorder was associated with positive outcomes for comorbid, untargeted mood and behavioural disorders in children and adolescents.

• Standard CBT protocols can be used as a valid approach when facing comorbidity.

• Other treatment strategies, such as transdiagnostic CBT or treating disorders individually, may not be needed.

• This indicates significant implications for treatment planning and implementation.

Abstract

Background

High rates of comorbidity among children and adolescents with anxiety disorders are widely documented. To date the question of what happens to comorbid disorders upon treatment of the primary anxiety disorder has received little attention and the optimal treatment strategy for cases with comorbidity remains to be determined.

Objectives

This review examines the literature on the impact of disorder-specific CBT on comorbid mood and behavioral disorders in young people with a primary anxiety disorder.

Search methods

PsycINFO, EMBASE, MEDLINE and the Cochrane Library were systematically searched using predefined selection criteria. Two reviewers independently assessed the relevance of studies, obtained data using a data extraction form and undertook methodological quality analysis.

Results

Ten studies (1647 children in total) were included in the review. All studies demonstrated positive outcomes for CBT focused on the primary anxiety disorder on untargeted comorbid mood and/or externalising disorders.

Conclusions

Findings suggest CBT focused on the primary anxiety disorder successfully reduces comorbid mood and/or behavioral diagnoses and symptoms of these co-occurring clinical diagnoses. Therefore, the implementation of disorder-specific CBT for the primary disorder is a valid alternative to transdiagnostic interventions and is recommended in cases of comorbidity in children and adolescents with a primary anxiety disorder.

Introduction

Anxiety disorders are one of the most prevalent forms of psychopathology in children and adolescents with prevalence rates of 5–19% (Costello et al., 2004). However, such disorders rarely occur in isolation and comorbidity with other mental health disorders is common. The definition of comorbidity adopted in this article is the co-occurrence of two or more disorders within the same individual (Allen et al., 2010, Brown and Barlow, 1992, Tsao et al., 2002, Tsao et al., 2005). High rates of comorbid disorders are widely established among anxiety-disordered youth, with up to 80% of young people diagnosed with a primary anxiety disorder also meeting criteria for a co-occurring disorder (Costello et al., 2004, Kendall et al., 2010, Rapee et al., 2013). High levels of comorbidity are found in both clinical and community samples (Chu and Harrison, 2007, Costello et al., 2004). The most frequent comorbid disorders presented are other anxiety disorders, mood disorders and externalizing disorders including Attention Deficit Hyperactivity Disorder (ADHD), Oppositional Defiant Disorder (ODD) and Conduct Disorder (CD) (Bernstein and Kinlan, 1997, Cummings et al., 2014, Lewinsohn et al., 1997, Merikangas et al., 2010).

Clinically there is a common assumption that the presence of a comorbid condition complicates and reduces treatment effectiveness (Kennard et al., 2005, Rapee et al., 2013). However, this assumption is not borne out by research findings. Ollendick et al. (2008) conducted a review examining the implications of comorbidity on treatment outcome. Fourteen of the 16 RCTs using CBT failed to report a significant difference between pre and post-treatment outcomes; the presence of a comorbid disorder did not affect treatment outcome. One study found a negative association between comorbid depression and poor treatment outcomes (Berman et al., 2000). However, whilst there is growing evidence that comorbidity does not affect treatment of the primary anxiety disorder, the optimal treatment for comorbid disorders in children and adolescents is unknown. Should (1) treatment focus on both disorders (‘transdiagnostic’) (2) treatment for one disorder precede treatment for another or (3) will the treatment of the primary disorder also affect the symptoms of the secondary disorder?

‘Transdiagnostic’ and ‘Modular’ approaches to comorbidity have attracted increasing attention in recent years (Marchette and Weisz, 2017). Transdiagnostic CBT aims to target core cognitive and behavioral processes that are assumed to be present across a range of disorders hence treating a range of conditions in a single treatment context (Andersen et al., 2016). Specifically, there has been an increased amount of empirical literature surrounding transdiagnostic CBT and anxiety disorders due to symptom overlap and the existence of common underlying psychopathology across the breadth of anxiety disorders (Barlow et al., 2004, Ehrenreich-May et al., 2017, Norton and Barrera, 2012). Modular approaches to comorbidity are equally valid (Weisz et al., 2012). However, such alternative approaches are in their relative infancy and it is important to understand how they compare in the treatment of comorbid disorders to the more established, traditional disorder-specific approaches such as CBT, which is the recommended optimal treatment for anxiety disorders (e.g. NICE, 2014) and is supported by an extensive body of literature in the treatment of anxiety disorders in children and adolescents (Cartwright-Hatton et al.,, Ishikawa et al., 2007, James et al., 2005, 2013).

The aim of this review was to determine the impact on comorbid disorders after treatment of the primary anxiety disorder in children and adolescents using CBT.