Is a specific phobia of vomiting part of the obsessive compulsive and related disorders?

Highlights

• Case review of individuals with a Specific Phobia of Vomiting (SPOV).

• Frequent report of repetitive behaviors such as compulsive washing and checking.

• These results have implications for the nosology and treatment of a SPOV.

• Clinicians should assess repetitive behaviors when formulating a treatment plan.

Abstract

Aims

To explore whether the phenomenology and co-morbidity of a specific phobia of vomiting (SPOV) (also known as “emetophobia”) might best fit within the group of obsessive compulsive and related disorders.

Method

Case review of individuals who were assessed for a SPOV (n=83).

Results

Sixty-two per-cent of cases reported being markedly or very severely preoccupied by the fear that they might vomit. A majority of people with a SPOV reported either often or always conducting repetitive behaviors such as compulsive washing; reassurance seeking; self-reassurance, counting or superstitious behaviors to prevent vomiting; checking others for signs of illness or checking sell-by dates. Cases that had more frequent hand washing were associated with higher scores on standardized questionnaires for a SPOV and a later age of onset. The diagnosis of OCD formed the highest degree of comorbidity.

Conclusions

The results have implications for future research into the nosology and treatment of a SPOV. Clinicians should assess for repetitive behaviors in a SPOV and include them in a formulation and treatment plan. Future research should conduct prospective studies to determine which aspects of the phenomenology of a SPOV might best fit under OC and related disorders.

Introduction

Obsessive Compulsive Disorder is characterized by the presence of obsessions and/or compulsions; avoidance behaviors are common. DSM-5 has a new section of obsessive compulsive and related disorders (OCRD) which includes body dysmorphic disorder, hoarding disorder, trichotillomania and skin-picking disorder (American Psychiatric Association, 2013). Stein and Philips (2014) noted that when considering the overall structure of DSM-5, 11 validators guided the workgroups. These were shared symptom similarity, neural substrates, comorbidity among disorders, biomarkers, course of illness, temperamental antecedents, shared familial ties, cognitive and emotional processing abnormalities, genetic risk factors, environmental risk factors, and treatment response. Based on these validators, it was decided to include a grouping of obsessive–compulsive and related disorders (OCRD), consisting of disorders that appear closely related to OCD.

The development of ICD-11 has also focused on the clinical utility of grouping certain disorders within the same chapter as well as validators (First, Reed, Hyman, & Saxena, 2015). Differences are emerging between the DSM-5 and planned ICD-11 in the group of OCRD. Thus, in contrast to DSM-5, there are plans to include hypochondriasis (illness anxiety disorder) in the OCRD section of ICD-11 (van den Heuvel, Veale, & Stein, 2014). For both DSM-5 and ICD-11, conditions such as obsessive–compulsive disorder (OCD), body dysmorphic disorder (BDD) and hypochondriasis are regarded as being more related to the anxiety disorders end of the spectrum than others, such as tics or trichotillomania.

We explore in this paper whether a specific phobia of vomiting (SPOV) (also known as emetophobia) should also be investigated as a potential OCRD. A SPOV is currently classified as a specific phobia (“Other type”) in DSM-5 (American Psychiatric Association, 2013) and in ICD-10 (World Health Organization, 1992). There are no plans to alter this classification in ICD-11 (Emmelkamp, 2012). However it is possible that ICD-11 working group may remove the sub-typing of specific phobias believing that there is no significant evidence for classifying subtypes (Emmelkamp, 2012).

A fear of vomiting is common in the community, affecting up to 7% of women and 1.8% of men (van Hout & Bouman, 2012). It appears, though, that a SPOV is rare. The only epidemiological survey that has specifically asked about a phobia of vomiting (Becker et al., 2007) found a prevalence of 0.1%. This may be an underestimate as clinical observations suggest that the symptoms may sometimes be confused with those of hypochondriacal disorder, obsessive–compulsive disorder and anorexia nervosa (Boschen, 2007, Manassis and Kalman, 1990, Veale, 2009). However, a co-morbid diagnosis of OCD should only be made in the presence of additional obsessions, unrelated to a fear of vomiting. An example could be the occurrence of additional checking behaviors to prevent harm, or magical thinking, designed to stop other bad events (not just vomiting). The avoidance behaviors in SPOV are well documented and are consistent with a phobia. People with a SPOV are likely to avoid situations or activities that could increase the risk of vomiting, such as being near people who are ill or drunk; fairground rides; boats; holidays abroad; travel by airplane; drinking alcohol; crowded places; public transport; eating from salad bars or buffets, or using public toilets (Lipsitz et al., 2001, Veale and Lambrou, 2006). They also use safety seeking behaviors when they feel nauseous and think they may vomit; for example they may look for an escape route; keep very still or try to keep tight control of their body; take anti-nausea medication; or try to distract themselves. They may also avoid certain foods or restrict their eating in order to reduce the risk of vomiting or amount of food vomited (Veale, Costa, Murphy, & Ellison, 2012). The phenomenology of repetitive behaviors or compulsions in SPOV has not been explored in detail. In his model, Boschen (2007) suggested that a preoccupation with one's gastrointestinal state resembles the bowel obsessions seen in some OCD cases. Some checking behavior (e.g., of whether food contains certain ingredients) was also noted in a non-clinical survey of individuals with SPOV (Lipsitz et al., 2001). A recent study found that the most common comorbid diagnosis in 64 individuals recruited over the internet with SPOV was of generalized anxiety disorder (28.1%), OCD (12.5%) and hypochondriasis (12.5%) (Sykes, Boschen, & Conlon, 2015). The aim of this study was to explore the comorbidity and frequency of repetitive behaviors and compulsions in more detail from the case notes in a clinical sample with SPOV. The study was therefore hypothesis generating to determine whether future studies on characteristics and validators of OCRD should include a group with a SPOV.