2005 overview: Key developments in the understanding and treatment of obsessive-compulsive disorder

Results from a number of studies that were published in 2005 have yielded new insights into the understanding and treatment of obsessive-compulsive disorder (OCD).

Nosology

The clinical heterogeneity of OCD can reduce the power and obscure the findings of research studies ranging from epidemiology to genome scans, neuroimaging, or clinical trials involving pharmacotherapy as well as psychotherapy

Attempts to split the disorder into mutually exclusive sub-types based on clinical characteristics (e.g., according to dominant compulsions such as washing, checking, hoarding) have yielded conflicting results. 

Multidimensional model

Mataix et al. (ref. 1) reviewed twelve factor-analytic studies that consistently extracted at least four symptom dimensions:

• symmetry/ordering
• hoarding
• contamination/cleaning
• obsessions/checking

These dimensions were associated with distinct patterns of comorbidity, genetic transmission, neural substrates, and treatment response.

Based on their findings, the authors propose a multidimensional model of OCD, representing a middle ground between the "lumping" and "splitting" perspectives. According to this model, the complex clinical presentation of OCD can be summarized with a few consistent, temporally stable symptom dimensions. These can be understood as a spectrum of potentially overlapping syndromes that may

• coexist in any patient
• be continuous with normal obsessive-compulsive phenomena
• extend beyond the traditional nosological boundaries of OCD

Epidemiology

Up to 25 years ago, OCD was considered a rare form of mental disorder. In the years following the publication of DSM-III, results from epidemiologic studies have shown consistently high prevalence rates.

According to Crino et al. (ref. 2), 12 month prevalence of OCD as defined by DSM-IV criteria is 0.6, i.e., considerable lower than for types of OCD based upon previous criteria. The current definition of OCD identifies a particularly severe type of OCD. In particular, OCD as defined by DSM-IV criteria is associated with considerable co-morbidity as well as with significant impairment.

Prevalence rates of mental disorders are influenced by a number of factors, including the type of diagnostic criteria used to define the disorder, the type of instrument used for assessing its signs and symptoms, or the degree of impairment required for a positive diagnosis.

It remains to be seen what definition is the most valid: a narrow definition, such as the one proposed in DSM-IV, which identifies a severe or "core" type of the disorder or a broader definition that includes less severe or subliminal types of the disorder, as part of an "OCD spectrum" of disorders.

Neuropsychology

In recent years, neuropsychologists have given increasing attention to the presence of neuropsychological deficits in OCD. There is, however, only limited evidence in favour of such deficits in OCD, and much of the existing data is conflicting.

Among potential neuropsychological deficits, the search for a deficit in memory has led to several investigations. In particular, a deficit in memory has been proposed to explain the checking behaviour in patients with OCD. According to this hypothesis, the checking compulsions observed in patients with OCD could be attempts to compensate for real or imagined forgetfulness.

Studies looking for a link between checking and memory problems have, however, produced equivocal results. In fact, most studies have been unable to detect a general memory deficit in patients with OCD.

No differences

In a study using state of the art methodology, Moritz et al. (ref. 3) did not find any differences in either memory or metamemory between patients with OCD and healthy controls. No differences were observed in either performance for overall memory (memory) or confidence in memory or in vividness of recognition (metamemory) between the two groups.

Future studies on memory and metamemory in OCD should investigate the memory of non-verbal, in particular motor stimuli, and explore indices of metamory that explore "feeling of knowing" or "feelings of doing”.

Brain imaging

OCD has been investigated extensively using both structural and functional neuroimaging techniques. Most studies have found abnormalities in a significant proportion of patients. As shown in a recent review by Friedlander and Desrocher (ref. 4), findings have not been consistent, however, across studies.

Nakao et al. (ref. 5) conducted a functional magnetic resonance imaging study involving brain activation of patients with obsessive-compulsive disorder during neuropsychological symptom provocation tasks before and after symptom improvement.

After symptom improvement, patients showed a decreased activation in frontal regions compared with pre-treatment activation and an increased activation in posterior regions compared with pre-treatment activation

Good vs. poor insight

Aigner et al. (ref. 6) have investigated the relative frequency of structural brain abnormalities in two subtypes of obsessive-compulsive disorder, namely OCD "with good insight" and OCD "with poor insight", using structural magnetic resonance imaging.

Most patients (83%) who had OCD with poor insight showed MRI abnormalities while such abnormalities were detected in only a minority of patients (21%) with good insight.  

Inconsistencies in MRI findings can be the result of many factors. Among the factors to be considered are variations in imaging techniques and analyses, sample size, comorbid disorders, age of onset, duration of illness, gender, and phenotypic heterogeneity.

Future brain imaging studies should take into account that OCD is probably not a homogenous disorder and results should be analysed taking into account major subtypes or dimensions, such as those that are characterized by washing, checking, hoarding, or insight

Immunology

OCD is part of a number of neuropsychiatric disorders that have been associated with basal ganglia dysfunction due to an aberrant post-streptococcal autoimmune response against neurones in the basal ganglia. The proposal that OCD may be mediated by autoimmune mechanisms has remained controversial however.

Dale et al. (ref. 7) have reported on the incidence of anti-brain antibodies (ABAB) in children with obsessive–compulsive disorder. A subgroup of children with OCD had ABGA findings similar to those seen in Sydenham’s chorea.

This finding suggests that auto-immunity may indeed play a role in the aetiology and/or maintenance of OCD, or of a subgroup of OCD. The presence of ABGA in the blood serum of patients with OCD cannot, however, by itself, be considered as a definite proof that anti-neuronal antibodies are involved in the origin of the disorder.

As pointed out by the authors themselves, such antibodies could be produced as a non-specific response to streptococcal infection, and, as such, represent a simple epiphenomenon or marker of the infection.

In spite of these limitations, this study represents an important contribution to a growing body of knowledge about the aetiology of OCD. If confirmed, the results could have major implications for the prevention of OCD, with in particular a possibility to prevent the occurrence of the disorder by means of a more systematic treatment of streptococcal infections with antibiotics. 

Treatment

Cottraux et al. (ref. 8) have reviewed the evidence-based literature concerning the efficacy and effectiveness of Cognitive-Behavioral Therapy (CBT) using exposure and ritual (or response) prevention (ERP), and pharmacotherapy including clomipramine and several selective serotonine reuptake inhibitors or SSRIs (citalopram, fluoxetine, fluvoxamine, paroxetine, and sertraline). Although there is no cure for OCD as yet, CBT and pharmacotherapy, either alone or in combination, are highly effective in the treatment of OCD.

Foa et al. (ref. 9) conducted a randomized, placebo-controlled trial of exposure and ritual prevention, clomipramine, and their combination in the treatment of OCD. Both ERP and clomipramine were efficacious, with the efficacy of ERP possibly superior to that of clomipramine. A combination of the two treatments did not present any advantage to what could be achieved with ERP alone.

CBT group therapy

As shown in a study by Braga et al. (ref. 10), CBR using ERP can be administered in groups.  The results of the study support the efficacy of CBT group therapy in the short and long term treatment of OCD. In particular, patients with full symptom remission after CBGT tended to maintain their gains over time. These are important finding since CBGT is much less expensive and time-consuming than individual CBT.

Unfortunately, a considerable proportion of sufferers do not benefit from those treatments, either because they cannot find a specialist to provide them, or because they do not know that such treatments exist.

As such, there is a need to bring these treatments, or at least part of them, to the attention of sufferers and to show them how they can best benefit from those treatments without or with only limited help by a professional. This is where self-managements interventions come in.

Self-help interventions

Barlow et al. (ref. 11) have published a review of self-management interventions for panic disorders, phobias and obsessive-compulsive disorders. Self-management interventions are a set of strategies used by people to manage the symptoms, treatment, and consequences of disorders.

Examples of self-help interventions include bibliotherapy, psychoeducation, computer-derived programs, and peer group interventions. They can be implemented when professional help is either unavailable, or when it is too costly, unwarranted, or not accepted by the patient.

Patients who are intellectually and emotionally capable to understand the nature of their disorder, as well as the types of treatment options that are currently available, and who are willing to invest considerable effort and time in the treatment of their disorder, may greatly profit from such interventions and techniques.

References

1. Mataix-Cols D, Conceicao do Rosario-Campos M and Leckman FL. A multidimensional model of obsessive-compulsive disorder. American Journal of Psychiatry 2005; 162 (2); 228-238

2. Crino R, Slade T and Andrews G. The changing prevalence and severity of obsessive-compulsive disorder criteria from DSM-III to DSM-IV. American Journal of Psychiatry 2005; 162 (5); 876-882

3. Moritz S, Jacobsen D, Willemborg B, Jelinek L and Fricke S. A check on the memory deficit hypothesis of obsessive-compulsive checking. European Archives of Psychiatry and Clinical Neuroscience 2005; 1-5

4. Friedlander L and Desrocher M. Neuroimaging studies of obsessive-compulsive disorder in adults and children. Clinical Psychology Review 2006; 26 (1); 32-49

5. Nakao T, Nakagawa A, Yoshiura T, Nakatani E, et al. Brain activation of patients with obsessive-compulsive disorder during neuropsychological and symptom provocation tasks before and after symptom improvement: a functional magnetic resonance imaging study. Biological Psychiatry 2005; 57 (8); 901-910

6. Aigner M, Zitterl W, Prayer D, Demal U, et al. Magnetic resonance imaging in patients with obsessive-compulsive disorder with good versus poor insight. Psychiatry Research: Neuroimaging 2005; 140 (2); 173-179

7. Dale RC, Heyman I, Giovannoni G and Church AW. Incidence of anti-brain antibodies in children with obsessive–compulsive disorder. British Journal of Psychiatry 2005; 187 (4); 314-319

8. Cottraux J, Bouvard MA and Milliery M. Combining pharmacotherapy with cognitive-behavioral intervention for obsessive-compulsive disorder. Cognitive Behaviour Therapy, 2005 34 (3); 185-192

9. Foa EB, Liebowitz, MR, Kozak MJ, Davies S, et al. Randomized, Placebo-Controlled Trial of Exposure and Ritual Prevention, Clomipramine, and Their Combination in the Treatment of Obsessive-Compulsive Disorder. American Journal of Psychiatry 2005; 162 (1); 151-161

10. Braga DT, Cordioli AV, Niederauer K and Manfro GG. Cognitive-behavioral group therapy for obsessive-compulsive disorder: a 1-year follow-up. Acta Psychiatrica Scandinavica 2005; 112 (3); 180-186.

11. Barlow JH, Ellard DR, Hainsworth JM, Jones FR and Fisher A. A review of self-management interventions for panic disorders, phobias and obsessive-compulsive disorders. Acta Psychiatrica Scandinavica 2005; 111 (4); 272-285