A clinician’s quick guide to evidence-based approaches: emetophobia (specific phobia of vomiting)

ABSTRACT

Emetophobia (a specific phobia of vomiting) is a chronic and disabling anxiety disorder. The current article reviews current conceptual models of the disorder. A list of assessment methods are described, and an evidence-based series of treatment components for use in formulation-based interventions are reviewed.

KEYWORDS:

• Cognitive behaviour therapy
• emetophobia
• phobia
• specific phobia of vomiting

Introduction

Emetophobia (a specific phobia of vomiting) is an anxiety disorder in which an individual experiences clinically significant levels of anxiety/fear related to the possibility of vomiting, or being around others who may vomit. It is associated with typical symptoms seen in other phobias, such as hypervigilance to threat, avoidance behaviours (e.g., foods, certain types of transport), and physical arousal (Boschen, 2007). It is typified by an early onset, and chronic course (Lipsitz et al., 2001). Emetophobia is also commonly comorbid with other psychological disorders, in particular obsessive-compulsive disorder and generalised anxiety disorder (Sykes et al., 2016).

Existing treatment guidelines

While there is a large body of previous research establishing the effectiveness of cognitive-behavioural interventions for anxiety disorders, including specific phobias, there are no specific treatment guidelines for emetophobia, apart from those published in journal articles (see below). Evidence-based treatments for emetophobia are proposed on the basis of similarities with other psychological disorders for which cognitive and behavioural interventions have been established (see below).

Useful overview for clinicians

• Boschen (2007) provided a thorough review and reconceptualization of phobia of vomiting, drawing on the basic cognitive and behavioural principles that have been successful in the formulation of other anxiety conditions. In this review, the author lists a series of formulation elements that were thought to cause and maintain the condition, specifically: a general anxiety vulnerability; a vulnerability to somatising anxiety as gastrointestinal upset; catastrophic misappraisal of gastrointestinal symptoms; hypervigilance to gastrointestinal cues or indications that others may be likely to vomit; thoughts and beliefs about the dangerousness and unacceptability of vomiting; nausea avoidance; and failure to obtain disconfirming evidence for vomit expectancies. Based on these causal/maintaining factors, a formulation-based treatment program was proposed, which included arousal management training, cognitive restructuring, distraction and attention training, and exposure therapy.

• Veale (2009) reviewed the existing literature on specific phobia of vomiting and proposed a “maintenance model” (p. 281) of the disorder. In this model, factors such as safety behaviours, predictions about the likelihood of vomiting, worry and self-reassurance, avoidance (experiential and of cues related to vomiting), hypervigilance, imagery, and self-focused attention were suggested to perpetuate the condition. Using this model, Veale proposed a cognitive-behavioural treatment approach in which exposure (to simulated vomit, the smell of butyric acid, vomiting-related video, and imaginal exposure of vomiting) is a key treatment component. Imagery rescripting, cognitive restructuring, and relinquishing safety behaviours are also proposed as important treatment components.

• Keyes et al. (2018) conducted an updated systematic review of the nature and treatment of specific phobia of vomiting. This review is the most comprehensive peer-reviewed summary of the research literature into emetophobia.

Evidence-based treatment manuals

• The treatment literature for emetophobia is dominated by single case, or small sample studies, with only one RCT published to date (Riddle-Walker et al., 2016). Although a treatment manual is not published for this program, the self-help book by Keyes and Veale (2021) is based on the treatment approach used in this research.

Self-help treatment manuals or books

There are several self-help books available to assist those with a fear of vomiting. Two of the most comprehensive are:

• Free Yourself from Emetophobia (Keyes & Veale, 2021) is a practical self-help manual based on the treatment protocol developed by Professor David Veale and colleagues in the United Kingdom, based on his cognitive-behavioural approach.

• The Emetophobia Manual (Goodman, 2020) is an inexpensive self-help book which guides the reader through a cognitive behavioural treatment approach. In addition to the text, the book includes links to other materials such as video which are used to aid treatment.

Evidence-based online or remote treatments or supports

There are numerous websites available which purport to provide treatments for emetophobia, but the effectiveness of these treatments is more difficult to determine. Some specifically claim that treatment of emetophobia should not include exposure, despite this being at odds with the suggestions of other published authors, and the sole RCT published by Riddle-Walker et al. (2016). As always, clinicians should ensure that they are satisfied with the evidence-base and professionalism of any website they are considering recommending to clients.

Assessment

Diagnostic interviews

• While there are no specific diagnostic interviews for emetophobia, other existing diagnostic interviews that assess the presence of phobia may be utilised in diagnosis of phobia of vomiting. They include the Structured Clinical Interview for DSM-5 Disorders (First et al., 2016), and the Anxiety and Related Disorders Interview Schedule for DSM-5 (Brown & Barlow, 2014).

Self-report and behavioural measures

Two self-report measures have been developed for the assessment of emetophobia. Both are freely available online or from the authors.

• The Emetophobia Questionnaire (EmetQ-13; Boschen et al., 2013) is a brief 13-item self-report measure of the severity of emetophobia symptoms. The scale shows a three-factor structure, measuring: avoidance of travel, movement, or certain locations; dangerousness of exposure to vomit/vomiting; and avoidance of others who may vomit. The measure shows good reliability in clinical emetophobic samples (α = .82), as well as being able to differentiate individuals with emetophobia from other anxiety disorders, and individuals from a non-clinical community sample. The EmetQ-13 is also sensitive to change due to treatment effects.

• The Emetophobia Behavioural Approach Test (Emet-BAT; Boschen et al., 2013) is included as an appendix in the validation study of the EmetQ-13. It provides a standardised behavioural measure of avoidance of a simulated vomit stimulus, and correlates moderately (r = .39) with the EmetQ-13. The vomit stimulus used in the approach test was suggested previously by McFadyen and Wyness (1983), and consists of “tinned rice, minestrone soup, parmesan cheese, vinegar, and sour milk” (p. 174).

• The Specific Phobia of Vomiting Inventory (SPOVI; Veale et al., 2013) is a 14-item self-report inventory to measure the severity of emetophobia symptoms. Items were generated using the results of a series of interviews with individuals with a phobia of vomiting (Veale & Lambrou, 2006). The measure shows high internal consistency in clinical samples (α = .91), as well as sensitivity to treatment effects and group differences between emetophobic and community samples. A cut-off score of 10 is suggested as a suitable balance between sensitivity (.97) and specificity (.98).

Take home messages about treatment

• Treatment of emetophobia should be formulation-based (Boschen & Oei, 2008), individualised, and rely on evidence-based treatment components. These include psychoeducation, arousal management skills, cognitive restructuring, and exposure to situations, locations, food, and other stimuli associated with the fear. This may include exposure to the experience of nausea, bloating, or fullness. Safety behaviours should be reduced or eliminated.

• Exposure to a convincing vomit-like substance can be used in treatment (see above). This formula can also be held in the mouth, allowing the clinician or an assistant to expose the client to the (simulated) act of someone vomiting.

• While exposure therapy is a cornerstone of treatment of phobias, we do not suggest that exposure to the act of vomiting is required in emetophobia. Additionally, the potential for adverse effects such as dental damage, or aspiration of vomitus may outweigh any likely benefits.

• As with treatment of all the anxiety disorders, there is a danger of return-of-fear even after successful treatment of emetophobia (Philips, 1985). Return of fear can be reduced by adherence to certain principles during exposure, such as longer exposure sessions (past the point of habituation), using a wide range of stimuli, completing exposure in multiple contexts, optimal timing of sessions, and ongoing homework exercises (Boschen et al., 2009).

New and emerging developments

Previous conceptual models and interventions for emetophobia have been primarily focused on application of standard cognitive and behavioural (exposure) techniques. As with other anxiety disorders, refinement of the application of these techniques (e.g., improving optimal delivery of exposure therapy) may lead to improved outcomes and/or more efficient delivery of treatment. The ongoing development of acceptance-based alternatives to cognitive restructuring, mindfulness-based approaches, and values-based behavioural changes (e.g., as seen in Acceptance and Commitment Therapy) may also provide benefit.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

Data sharing is not applicable to this article as no new data were created or analysed in this study.