Obsessive compulsive disorder: a review

Obsessive-compulsive disorder (OCD) is characterised by the presence of obsessions or compulsions, or commonly of both. OCD is the fourth most common mental disorder after depression, alcohol/substance misuse, and social phobia, with a lifetime prevalence in community surveys of 1.6%.1 The severity of OCD differs markedly from one person to another. People are often able to hide their OCD, even from their own family, although it can cause problems in relationships and interfere with the ability to study or work. Health consequences can also occur: fear of contamination can, for example, prevent the accessing of appropriate health services or lead to dermatitis from excessive washing. When the disorder starts in childhood or adolescence, young people may avoid socialising with peers or become unable to live independently. The World Health Organization ranks OCD as one of the 10 most handicapping conditions by lost income and decreased quality of life.2 This clinical review summarises the evidence on how to recognise, assess, and manage people with OCD

Mass spectrometry-based methods for characterizing transient protein–protein interactions

The dynamic associations of transient protein–protein interactions (PPIs) are critical mediators of myriad biochemical processes. These specific, low-affinity interactions are often mediated by conserved amino acid sequences or short linear motifs (SLiMs) that interact with corresponding binding domains. The short-lived and dynamic nature of these interactions make their biophysical characterization a significant challenge. This review focuses on the development and future directions of mass spectrometry (MS)-based techniques for elucidating and characterizing SLiM-mediated PPIs. This includes the application of protein footprinting techniques to infer the location of SLiM binding sites and the growing role of native MS for direct observation of protein–SLiM interactions, highlighting their potential for the assessment of small molecule modulation of transient PPIs and the identification of interfacial SLiMs.</p

Cognitive deficits in obsessive compulsive disorder in tests which are sensitive to frontal lobe dysfunction

Forty patients with obsessive compulsive disorder (OCD) were compared to matched healthy controls on neuropsychological tests which are sensitive to frontal lobe dysfunction. On a computerised version of the Tower of London task of planning, OCD patients were no different to healthy controls in the accuracy of their solutions. There was no difference between the groups in the time spent thinking prior to making the first move or in the time spent thinking after the first move when "perfect move" solutions were considered. However, when the patients made a mistake, they spent more time than the controls generating alternative solutions or checking that the next move would be correct. The results suggest that OCD patients have a selective deficit in planning of generating alternative strategies when they make a mistake. In a separate attentional set-shifting task, OCD patients showed a continuous increase in terms of the number who failed at each stage of the task, including the crucial extra- dimensional set shifting stage. This suggests that OCD patients show deficits in both acquiring and maintaining cognitive sets. A sub-group of OCD patients who fail at or before the extra-dimensional shift stage also performed poorly on the Tower of London task. They are less accurate when solving problems and have a similar pattern of deficits to some neurosurgical patients with frontal lobe excisions. Both studies support the evidence of frontal-striatal dysfunction in OCD and the pattern of results is compared to that found in other known fronto-striatal disorders. The results are discussed in terms of a functional absence of a Supervisory Attentional System (Norman and Shallice, 1980)

The Cognitive Behavioural Processes Questionnaire: A Preliminary Analysis within Student, Mixed Clinical and Community Samples and the Identification of a Core Transdiagnostic Process

Theorists have highlighted the commonalities in cognitive and behavioural processes across multiple disorders i.e. transdiagnostic approach. We report two studies that tested the psychometric properties of a new scale to assess these processes. The Cognitive and Behavioural Processes Questionnaire (CBP-Q) was developed as a 15- item measure. In Study 1, the CBP-Q was administered to a student (n = 172) sample with a range of standardised measures of the processes and symptom measures. Study 2 repeated the evaluation in a mixed clinical group (n = 161) and a community control group (n = 57). An exploratory factor analysis resulted in a 12-item version of the CBPQ, consisting of a single factor. The measure demonstrated good internal consistency, test-retest stability and satisfactory convergent and divergent validity in both studies. Correlations with symptom-based measures showed increased engagement in these cognitive and behavioural processes to be associated with higher levels of symptomatology. The scale was elevated in the clinical relative to the community group and there were no differences in scores between broad diagnostic groupings (anxiety vs. mood vs. other). The CBP-Q has good psychometric properties. The findings are consistent with the transdiagnostic approach and indicate that a single, as yet unspecified factor may account for the shared variance across cognitive and behavioural maintenance processes