OCD: Towards DSM-V

Obsessive-compulsive disorder (OCD) is a prevalent disorder, affecting up to 2.3% of the population 1. The symptomatology and the timecourse of the disease both contribute to its debilitating effects on the individual: it is often chronic and in many cases is associated with an inability to work, a decrease in social functioning, low self-esteem, and increased suicidality 2.

At present, OCD is classified in the Diagnostic and Statistical Manual of Mental Disorders IV (DSM-IV-TR) 3 (but not in the ICD10) as an anxiety disorder. Although OCD and other anxiety disorders may share some characteristics, there is currently only one specifier in DSM-IV-TR for OCD: ‘poor insight’. There are many behavioral, phenomenological and biological features of OCD which make it distinct from other anxiety disorders, and could be used as specifiers to help diagnosis. These include symmetry and ordering possessions, hoarding, repeated washing/fear of contamination, and doubt leading to repeated checking.

In addition, the concept of subtyping could be introduced to the classification of OCD. Two of the most obvious subtypes are early onset, male, tic-related OCD, associated with symmetry compulsion and OCD with poor insight. Unlike other anxiety disorders, it is not uncommon for symptoms of OCD to manifest prepubertally. In other cases where onset occurs during adulthood, it is often triggered by psychological trauma 4. Although the type and frequency of the traumas preceding OCD diagnosis may be important 5, 6, patients are often unable to identify specific events that precipitated the disease 5.

Furthermore, there are several closely associated disorders which the OCD “umbrella” might extend to, as they are increasingly recognized as part of the dimension. These include body dysmorphic disorder, Tourette's syndrome and other tic disorders, hypochondriasis, OC personality disorder, and grooming behavior (e.g., hair-pulling, nail-biting and skin-picking).

The etiology of OCD may also be linked to the nature of the emotional trauma triggering the disease. Thus, people exposed to combat or sexual abuse may manifest a specific cluster of symptoms 7. For example, in a recent study of 13 military veterans, onset of OCD surfaced shortly after the onset of post-traumatic stress disorder (PTSD) 8. Moreover, the symptomatology presented by the patients was, in many cases, associated with specific characteristics of their individual experiences (Table I). Thus, recollections of seeing other people die caused OCD involving a need for symmetry and precision. OCD symptoms involving feelings of contamination and repeated washing were ubiquitous across this population, due to common recollections of blood, physical trauma and/or abuse associated with feelings of “disgust”.

Table I.  Type of OCD and link to specific trauma for 13 military veterans. Reprinted with permission from 8 copyright (2005), with permission from Elsevier.

Subject no.	Duration of PTSD (years)	Duration of OCD (years)	Type of OCD	Link to trauma
1	4	4	Contamination, washing	Intrusive recollection of body covered with flesh of terrorist evoked OCD
2	27	27	Contamination, washing, symmetry and precision	Recollection of holding dead bodies evoked OCD
3	27	27	Contamination, washing, symmetry and precision	Recollection of sexual abuse evoked OCD
4	15	15	Contamination, washing	Recollection of blood and dirt on body from holding dead bodies
6	27	27	Contamination, somatic, pathological doubt, washing	Recollection of sexual and physical abuse in captivity
7	18	18	Contamination, need for symmetry, washing, symmetry and precision	Recollection of helplessness on seeing soldier under his command die and of being unable to identify dead bodies
8	1	1	Contamination, washing, checking	Recollection of oil burning his body
9	11	11	Washing, counting, checking	Recollection of his face being cut, of being washed in blood
10	4	4	Contamination, washing	Recollection of wounded enemy soldier he shot
11	10	10	Contamination, washing, hoarding	Recollection of physical abuse while in captivity by prisoners in jail
12	43	43	Pathological doubt, checking, counting	Recollection of accidentally lighting a fatal fire
13	2	2	Contamination, washing, symmetry and precision	Recollection of body burning during explosion
Mean	14.5	14.5

The marked link between OCD and PTSD raises the possibility of a common etiology. Thus, should OCD stemming from trauma be classed as a distinct subtype? With more research into the vast array of OCD symptoms and comorbid mood and anxiety disorders, further subgroups may be identified. The current rates of diagnosis are relatively low, and the period from onset of symptoms up to the time that a correct diagnosis is made, may be as long as 15 years 2. However, this could be improved by an expansion of our understanding of OCD.

Several national and international organizations have published guidelines for the diagnosis and treatment of OCD during the last 5 years (2006: Canadian, APA; 2005: NICE; 2003: BAP, WCA; 2002: WFSBP). The most common treatment recommendation is a combination of pharmacological (selective serotonin reuptake inhibitors; SSRIs) and cognitive behavioral therapy (CBT). The recent guidelines from NICE (www.NICE.org) have been proactive with regard to diagnosis and include specific recommendations such as promoting awareness of OCD as a major lifespan disorder, encouraging the incorporation of a stepped-care model to improve access to specialist services, and widening the availability of pharmacotherapy and CBT as first-line therapy for adults. To help identify sufferers of OCD, NICE – in collaboration with clinicians (J. Zohar and N. Fineberg) – have developed a set of five key questions:

• Do you check things a lot?

• Do you wash or clean a lot?

• Is there any thought that keeps bothering you that you would like to get rid of but can't?

• Do your daily activities take a very long time to finish?

• Are you concerned about orderliness or symmetry?

This screening tool can improve rates of diagnosis and hopefully reduce the lag between onset of symptoms and appropriate treatment.

As we look to the future of mental healthcare, technological advances may allow radical changes and improvements in the way we diagnose and treat disorders such as OCD. Instead of diagnosing OCD by symptoms and then treating those symptoms as we do today, the projected development of proteomics and molecular diagnostics over the next 20 years or so will hopefully enable strategic prevention and treatment of the core pathology, leading to real ‘cures’ rather than symptom remission (Figure 1). This is a long-term goal, and the Lundbeck-sponsored satellite symposium held on 19 September, in Paris, at the 19th Congress of the European College of Neuropsychopharmacology (ECNP) represents one small step towards achieving this goal.

Figure 1.  Future treatment and disease prevention goals in mental health. Adapted and reprinted from 9 copyright (2005) with permission of John Wiley & Sons, Inc.

The subject of the symposium and the proceedings articles which follow in this issue is: “Obsessive spectrum disorders over the life cycle”, with a focus on OCD and its classification in the future 5th edition of the Diagnostic and Statistical Manual (DSM-V). This edition of DSM is expected in 2011 (www.APA.org). If the new edition is to offer improved guidance for diagnosis and revised treatment methods, physicians need to collaborate in order to reassess the current classification of OCD in light of recent evidence. This was the aim of the symposium. In the proceedings articles which follow, experts in the field of OCD disseminate the most recent preclinical and clinical findings on the categorization, underlying pathophysiology, symptomatology, and treatment of OCD.

In the first presentation, Professor Eric Hollander discussed the developmental trajectory of anxiety disorders over the life span. After describing the complex nature of OCD with consequent difficulties for diagnosis and treatment, he examined the current classification of OCD in the DSM-IV-TR with a review of a suggested re-classification in the future DSM-V. One proposal is that OCD should not be classed as an anxiety disorder, but grouped with several related disorders, collectively called obsessive-compulsive related disorders (OCRD). The rationale for linking these disorders is based on shared symptoms, underlying pathophysiology, brain circuitry, and treatment response. This would be more consistent with the WHO International Statistical Classification of Diseases and Related Health Problems (ICD) system, which places OCD in a separate diagnostic category from anxiety disorders.

In February 2006, an international group of experts met in Cape Town, South Africa, to review the latest scientific data relating to the symptomatology, diagnosis, neurobiology and treatment of OCD. The consensus statement resulting from this meeting was the subject of the second presentation, by Professor Dan Stein. He argued that clinical utility of the DSM-IV-TR entry for OCD may ultimately be enhanced by a revised classification in DSM-V that identifies common phenomenological and psychobiological dimensions across a range of obsessive-compulsive disorders. This grouping may include hoarding, Tourette's syndrome, body dysmorphic disorder, and eating disorders.

The third presentation was given by Professor Pierre Blier on the importance of serotonin (5-HT) and noradrenaline (NA) in anxiety. The selective serotonin reuptake inhibitors (SSRIs) are the only class of drugs consistently effective for the treatment of OCD, thus highlighting the importance of the 5-HT system in the pathophysiology of OCD. Professor Blier described preclinical studies in which long-term administration of SSRIs enhanced 5-HT transmission, partly by desensitization of terminal 5-HT autoreceptors. The clinical relevance of the reciprocal activity between the 5-HT system and the noradrenaline (NA) system was examined. Differences in the effectiveness of various SSRIs are due to different underlying mechanisms of action. The unique mode of action of escitalopram enables greater extracellular 5-HT levels than the racemic citalopram, making escitalopram a viable treatment option for depression, anxiety disorders and OCD.

New treatment options for OCD were discussed by Professor Naomi Fineberg in the last presentation of the session. Current pharmacological treatments for OCD were described, along with their associated side-effects. The greater tolerability profile of the SSRIs compared with the tricyclic antidepressant drug, clomipramine, suggests that SSRIs are the treatment of choice. Escitalopram (the active S-enantiomer of the racemic citalopram) is the most selective of the SSRIs available. Clinical studies have shown that escitalopram 20 mg/day is associated with numerically greater remission rates than paroxetine 40 mg/day after 12 weeks of treatment. Greater relapse prevention has also been demonstrated for esciptalopram 10 and 20 mg/day, relative to placebo. Professor Fineberg concluded that escitalopram should be considered as a first-line, long-term, pharmacotherapy for OCD.

Overall, this supplement represents an important step towards a new conceptualization and greater understanding of OCD, by highlighting the latest preclinical and clinical evidence to support a suggested reclassification of OCD in the future DSM-V. Such a reclassification may have clinical corollaries, including improved diagnostic validity for OCD and OCD-related disorders, along with greater recognition rates. Patients may therefore benefit sooner from the administration of effective pharmacotherapy, such as SSRIs, including the most selective 5-HT re-uptake inhibitor, escitalopram.

Statement of interest

The author has received research grants from Pfizer and Lundbeck Institute, is a member of Advisory Boards for Pfizer, Lundbeck and Actelion and of the speaking bureaus of Solvay, Lundbeck and Wyeth.