Search

Obsessive–compulsive disorder (OCD) is a clinically heterogeneous disorder characterized by multiple, temporally stable symptom dimensions. Preliminary functional neuroimaging studies suggest that these symptom dimensions may have distinct neural substrates. Whole-brain voxel-based morphometry was used to examine the common and distinct neuroanatomical (structural) substrates of the major symptom dimensions of OCD. First, we compared 55 medication-free patients with OCD and 50 age-matched healthy control subjects. Multiple regression analyses were then used to examine the relationship between global and regional grey matter (GM) and white matter (WM) volumes and symptom dimension scores within the patient group. OCD patients showed decreased GM volume in left lateral orbitofrontal (BA47), left inferior frontal (BA44/45), left dorsolateral prefrontal (BA9) and right medial prefrontal (BA10) cortices and decreased bilateral prefrontal WM volume. Scores on the ‘symmetry/ordering’ dimension were negatively correlated with ‘global’ GM and WM volumes. Scores on the ‘contamination/washing’ dimension were negatively correlated with ‘regional’ GM volume in bilateral caudate nucleus and WM volume in right parietal region. Scores on the ‘harm/checking’ dimension were negatively correlated with regional GM and WM volume in bilateral temporal lobes. Scores on the ‘symmetry/ordering’ dimension were negatively correlated with regional GM volume in right motor cortex, left insula and left parietal cortex and positively correlated with bilateral temporal GM and WM volume. The results remained significant after controlling for age, sex, educational level, overall illness severity, global WM and GM volumes and excluding patients with comorbid depression. The reported symptom dimension-specific GM and WM alterations support the hypothesis that OCD is an etiologically heterogeneous disorder, with both overlapping and distinct neural correlates across symptom dimensions. These results have clear implications for the current neuroanatomical model of OCD and call for a substantial revision of such model which takes into account the heterogeneity of the disorder. [ABSTRACT FROM AUTHOR]

Background: There is accumulating evidence for the role of fronto-striatal and associated circuits in obsessive-compulsive disorder (OCD) but limited and conflicting data on alterations in cortical thickness., Aims: To investigate alterations in cortical thickness and subcortical volume in OCD., Method: In total, 412 patients with OCD and 368 healthy adults underwent magnetic resonance imaging scans. Between-group analysis of covariance of cortical thickness and subcortical volumes was performed and regression analyses undertaken., Results: Significantly decreased cortical thickness was found in the OCD group compared with controls in the superior and inferior frontal, precentral, posterior cingulate, middle temporal, inferior parietal and precuneus gyri. There was also a group × age interaction in the parietal cortex, with increased thinning with age in the OCD group relative to controls., Conclusions: Our findings are partially consistent with earlier work, suggesting that group differences in grey matter volume and cortical thickness could relate to the same underlying pathology of OCD. They partially support a frontostriatal model of OCD, but also suggest that limbic, temporal and parietal regions play a role in the pathophysiology of the disorder. The group × age interaction effects may be the result of altered neuroplasticity., (© The Royal College of Psychiatrists 2017.)

Background: Obsessive-compulsive disorder (OCD) has similar prevalence rates across ethnic groups. However, ethnic minorities are underrepresented in clinical trials of OCD. It is unclear whether this is also the case in clinical services., Aims: To explore whether ethnic minorities with OCD are underrepresented in secondary and tertiary mental health services in the South London and Maudsley (SLaM) NHS Foundation Trust., Method: The ethnic distribution of patients with OCD seen between 1999 and 2013 in SLaM (n = 1528) was compared with that of the general population in the catchment area using census data. A cohort of patients with depression (n = 22 716) was used for comparative purposes., Results: Ethnic minorities with OCD were severely underrepresented across services (-57%, 95% CI -62% to -52%). The magnitude of the observed inequalities was significantly more pronounced than in depression (-29%, 95% CI -31% to -27%)., Conclusions: There is a clear need to understand the reasons behind such ethnic inequalities and implement measures to reduce them., (© The Royal College of Psychiatrists 2015.)

A partial N-methyl-D-aspartate agonist, D-cycloserine, enhances fear extinction when given before or shortly after exposure to feared stimuli in animals. In this pilot double-blind placebo-controlled trial (trial number: ISRCTN70977225), 27 youth with obsessive-compulsive disorder were randomised to either 50 mg D-cycloserine or placebo administered immediately after each of ten cognitive-behavioural therapy (CBT) sessions, primarily consisting of exposure and ritual prevention. Both groups improved significantly and maintained their gains at 1-year follow-up, with no significant advantage of D-cycloserine over placebo at any time point. The effects of CBT may not be augmented or accelerated when D-cycloserine is administered after sessions.

Background: Hoarding disorder is typified by persistent difficulties discarding possessions, resulting in significant clutter that obstructs the individual's living environment and produces considerable functional impairment. The prevalence of hoarding disorder, as defined in DSM-5, is currently unknown., Aims: To provide a prevalence estimate specific to DSM-5 hoarding disorder and to delineate the demographic, behavioural and health features that characterise individuals with the disorder., Method: We conducted a two-wave epidemiological study of 1698 adult individuals, originally recruited via the South East London Community Health (SELCoH) study. Participants screening positively for hoarding difficulties in wave 1, and who agreed to be re-contacted for wave 2 (n = 99), underwent in-home psychiatric interviews and completed a battery of self-report questionnaires. Current DSM-5 diagnoses were made via consensus diagnostic procedure., Results: In total, 19 individuals met DSM-5 criteria for hoarding disorder at the time of interview, corresponding to a weighted prevalence of 1.5% (95% CI 0.7-2.2). Those with hoarding disorder were older and more often unmarried (67%). Members of this group were also more likely to be impaired by a current physical health condition (52.6%) or comorbid mental disorder (58%), and to claim benefits as a result of these issues (47.4%). Individuals with hoarding disorder were also more likely to report lifetime use of mental health services, although access in the past year was less frequent., Conclusions: With a lower-bound prevalence of approximately 1.5%, hoarding disorder presents as a condition that affects people of both genders and is associated with substantial adversity.