How does “Pure-O” obsessive-compulsive disorder impact on a patient’s treatment plan?

KEYWORDS:

• OCD
• Pure-O
• treatment preditctors
• symptom dimensions
• SSRI
• CBT

1. Introduction

Obsessive-compulsive disorder (OCD) is a heterogenous disorder, with several sub-classifications having been proposed in the past and present literatures. For instance, some authors have proposed a sub-classification according to comorbidity patterns, natural course (episodic vs chronic), age of onset (early vs late onset), symptoms dimensions, etc [1]. In all of these sub-classifications, the OCD clinical picture is still characterized by the presence of obsessions and compulsions. However, in recent years, it has become more common for clinicians to receive requests from patients seeking treatment for a putative subtype of OCD called ‘Pure-O,’ which is characterized by the partial or even complete absence of compulsions (that are only mental). A dedicated Wikipedia page states that ‘Primarily obsessional obsessive – compulsive disorder (OCD), also known as purely obsessional obsessive – compulsive disorder (Pure O), is a lesser-known form or manifestation of OCD … ’ and in this form of OCD ‘ … there are fewer observable compulsions, compared to those commonly seen with the typical form of OCD’ [2]. Furthermore, many informative websites and social network pages on mental health have assumed the existence of a primarily obsessional form of OCD. On most of these websites, this form of OCD is highlighted by the fact that compulsions are fewer (if not totally absent) and are mostly mental. These dedicated websites also report that the themes of Pure-O symptoms are typically related to aggressive, religious, or sexual content. While the definition of the Pure-O varies across the internet, most of them do not provide any criticism about the true existence of this putative subtype of OCD. Thus, a patient seeking information about his intrusive thoughts for the first time could easily believe that he suffers from a widely recognized disorder called Pure-O. However, its existence is not recognized in the current OCD literature. Although the ICD-11 and the DSM-5 state that OCD is characterized by the presence of obsessions or compulsions or most commonly both, they do not formalize the existence of an only-obsessional or only-compulsive OCD sub-type. This definition rather emphasizes the fact that, for some patients, detecting both obsessions and compulsions could be challenging for clinicians.

2. Origins of the (mis)conception of “Pure-O”

A possible origin for this Pure-O subtype could be situated in some early studies dedicated to OCD symptom dimensions that took place more than 20 years ago. In those studies, the authors hypothesized the presence of an OCD symptom dimension of aggressive/sexual/religious obsessions that was characterized by the absence of compulsions [3–5]. However, subsequent studies clearly showed that patients with aggressive, sexual, and religious obsessions actually perform compulsions by engaging in mental rituals and through the demand for reassurance [6]. Consequently, this so-called Pure-O subtype is nothing more and nothing less than a typical form of OCD characterized by the co-presence of obsessions and compulsions. Indeed, considering Pure-O as a subtype of OCD has no scientific evidence and, moreover, could be potentially harmful or at least confounding for patients seeking treatment or patients with specific obsessions (e.g. patients with doubts on their mental state and mental disorders).

3. Symptom dimensions as treatment moderators

Subtyping OCD according to symptoms dimensions (e.g. aggressive/religious/sexual symptoms such as has been with Pure-O) could be relevant in order to identify clinical predictors of different treatment approaches. Serotonergic agents (serotonin reuptake-inhibitors, SRIs) and cognitive-behavioral therapy (CBT) with Exposure and Response Prevention (ERP) technique are widely considered as the first-line approaches for treating OCD patients. While data from the first controlled trials on serotonergic agents suggested that the presence of hoarding-related OCD symptoms to be a predictor of non-response, subsequent studies and long-term longitudinal studies did not find a clear association between specific symptom dimensions and long-term outcome with serotonergic agents [7,8]. Thus, the presence of sexual/religious/aggressive symptoms (as found in so-called Pure-O) is not a factor that can influence the pharmacological approach for an OCD patient. The evidence concerning the CBT/ERP approach is more mixed. Studies on pediatric and adolescent samples of OCD patients consistently did not find a significant impact of aggressive symptom dimensions on CBT outcome [9,10]. On the other hand, some trials on adults found that baseline sexual/religious symptoms predicted a worse outcome [11]. However, an early CBT trial showed that patients with these dimensions are likely to improve as well as the patients suffering with symptoms from other dimensions when these symptoms are included in the functional analysis and addressed using CBT [12]. Several factors could be potentially related to the worse outcome observed in some CBT trials. For instance, there could be situations in which patients struggle with the shame of admitting and facing taboo thoughts and images or where the clinician fails to address how subtle mental compulsions, avoidance, and reassurance maintain the disorder. Consequently, having sexual/religious/aggressive compulsions are not universal predictors of non-response to CBT, but rather illustrates a challenging clinical picture where clinicians need to pay greater attention to their initial assessment in order to correctly identify and bring in the best suited treatment plan to tackle the presence of taboo themes and hidden mental compulsions or avoidant behaviors.

4. Expert opinion

So-called ‘Pure-O’ is not a recognized subtype of OCD but is instead a classic form of OCD characterized by aggressive/religious and sexual obsessions and compulsions (that are often mental and challenging to recognize). To date, the available literature does not seem to suggest a ‘moderator effect’ on the treatment outcome of these particular symptom dimensions with first-line medications. Also, when these symptom dimensions are correctly identified and brought into the treatment plan, they do not seem to have a negative impact on psychotherapeutic approaches (CBT/ERP). By the same token, patients who are identified by this so-called ‘Pure-O’ concept represent a population that could be potentially challenging to treat with psychotherapy. Thus, a future goal of the current literature should be to better understand how the presence of mental rituals and/or avoidance behaviors (or in general ‘hidden’ compulsions) could potentially affect the psychotherapy treatment process and also how the recognition of compulsions in these patients should be improved during the clinical assessment.

Finally, the case of ‘Pure-O’ further highlights the importance of filling the gap between the academic and the ‘virtual’ world. In this era, people look for a better understanding and seek for the appropriate help for their mental health problems firstly through the web. Providing reliable and evidence-based information across dedicated social networks and websites is a relevant step in order to reduce the mental health stigma and to help people better recognize their mental issues.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This manuscript was not funded.