Browsing by Author "Lochner C."
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- ItemDifferential effects of escitalopram challenge on disgust processing in obsessive-compulsive disorder(2012) Lochner C.; Simmons C.; Kidd Michael; Chamberlain S.R.; Fineberg N.A.; van Honk J.; Ipser J.; Stein D.J.
- ItemDopamine transporter binding in social anxiety disorder: The effect of treatment with escitalopram(2012) Warwick, James M.; Carey P.D.; Cassimjee N.; Lochner C.; Hemmings, Sian M. J.; Moolman-Smook H.; Beetge E.; Dupont P.; Stein D.J.Social anxiety disorder (SAD) is characterised by fear of social or performance situations where the individual is exposed to unfamiliar people or to possible scrutiny by others. The literature on dopamine ligands and dopamine genotypes in SAD is however inconsistent. In this study we measured the effects of SSRI pharmacotherapy on dopamine transporter (DAT) binding in patients with SAD, also addressing variability in DAT genotype. Adult subjects meeting DSM-IV criteria for generalised SAD were studied before and after 12 weeks of pharmacotherapy with the selective serotonin reuptake inhibitor (SSRI) escitalopram. DAT single photon emission computed tomography (SPECT) using 123I-FP-CIT was performed at baseline, and repeated at 12 weeks. Striatal DAT binding was analysed for changes following therapy, and for correlations with clinical efficacy, in the whole group as well as for a subgroup with the A10/A10 DAT genotype. The study included 14 subjects (9 male, 5 female) with a mean (SD) age of 41 (±13) years. The subjects' Liebowitz Social Anxiety Scale (LSAS) score was significantly decreased following pharmacotherapy. In the combined group the left caudate and left putamen showed clusters of increased DAT binding after therapy. The left caudate changes were also observed in the subgroup of 9 A10/A10 homozygotes. However no correlation was found between improved symptoms and DAT binding. The changes found in DAT binding in the caudate and putamen may be due to serotonergic activation of dopamine function by SSRI therapy. This is consistent with previous work indicating decreased DAT binding in SAD, and increased DAT binding after SSRI administration. © Springer Science+Business Media, LLC 2012.
- ItemEvidence for fractional anisotropy and mean diffusivity white matter abnormalities in the internal capsule and cingulum in patients with obsessive-compulsive disorder(2012) Lochner C.; Fouche J.-P.; du Plessis S.; Spottiswoode B.; Seedat S.; Fineberg N.; Chamberlain S.R.; Stein D.J.Background: There is evidence to suggest that obsessive-compulsive disorder (OCD) is associated with structural abnormalities in cortico-striato-thalamic circuits, yet the extent of white matter abnormalities is not well established. In this study, we used diffusion tensor imaging (DTI) to examine white matter integrity in specific regions of interest (ROIs) in patients with OCD. Methods: Patients with OCD and sex-, age- and IQ-matched healthy controls underwent DTI. The primary objective was to explore whether patients with OCD had white matter abnormalities in the anterior limb of the internal capsule (ALIC), the uncinate fasciculus, the genu of the corpus callo-sum and the cingulum. The secondary objective was to evaluate the relation between fractional anisotropy and mean diffusivity in these ROIs and other clinical variables (including age at onset of OCD, OCD severity and levels of depressive and anxiety symptomatology) in patients with OCD. Results: There were 15 patients and 17 controls enrolled in our study. Compared with healthy controls, patients with OCD showed increased fractional anisotropy in bilateral regions of the ALIC adjacent to the body of the caudate, as well as decreased fractional anisotropy in the right anterior limb near the head of the caudate. Patients also had decreased mean diffusivity in the body of the right cingulum and the left anterior cingulum compared with controls. Correlational analyses revealed significant associations of fractional anisotropy and mean diffusivity in select circuits with OCD, depression and anxiety severity scores. Limitations: Inclusion of patients with OCD receiving pharmacotherapy may have been a limitation. In addition, the patients were heterogeneous in terms of their obsessive-compulsive symptom profiles; we did not distinguish between different obsessive-compulsive symptom dimensions. Conclusion: The study results provide further evidence for OCD-related white matter abnormalities in the ALIC and cingulum, consistent with a cortico striatal model of OCD. © 2012 Canadian Medical Association.
- ItemGrey matter abnormalities in social anxiety disorder: A pilot study(2012) Syal S.; Hattingh C.J.; Fouche J.-P.; Spottiswoode B.; Carey P.D.; Lochner C.; Stein D.J.While a number of studies have explored the functional neuroanatomy of social anxiety disorder (SAD), data on grey matter integrity are lacking. We conducted structural MRI scans to examine the cortical thickness of grey matter in individuals with SAD. 13 unmedicated adult patients with a primary diagnosis of generalized social anxiety disorder and 13 demographically (age, gender and education) matched healthy controls underwent 3T structural magnetic resonance imaging. Cortical thickness and subcortical volumes were estimated using an automated algorithm (Freesurfer Version 4.5). Compared to controls, social anxiety disorder patients showed significant bilateral cortical thinning in the fusiform and post central regions. Additionally, right hemisphere specific thinning was found in the frontal, temporal, parietal and insular cortices of individuals with social anxiety disorder. Although uncorrected cortical grey matter volumes were significantly lower in individuals with SAD, we did not detect volumetric differences in corrected amygdala, hippocampal or cortical grey matter volumes across study groups. Structural differences in grey matter thickness between SAD patients and controls highlight the diffuse neuroanatomical networks involved in both social anxiety and social behavior. Additional work is needed to investigate the causal mechanisms involved in such structural abnormalities in SAD. © Springer Science+Business Media, LLC 2012.
- ItemLatent class analysis of the Yale-Brown Obsessive-Compulsive Scale symptoms in obsessive-compulsive disorder(2011) Delucchi K.L.; Katerberg H.; Stewart S.E.; Denys D.A.J.P.; Lochner C.; Stack D.E.; Den Boer J.A.; Van Balkom A.J.L.M.; Jenike M.A.; Stein D.J.; Cath D.C.; Mathews C.A.Objective: Obsessive-compulsive disorder (OCD) is phenomenologically heterogeneous, and findings of underlying structure classification based on symptom grouping have been ambiguous to date. Variable-centered approaches, primarily factor analysis, have been used to identify homogeneous groups of symptoms; but person-centered latent methods have seen little use. This study was designed to uncover sets of homogeneous groupings within 1611 individuals with OCD based on symptoms. Method: Latent class analysis models using 61 obsessive-compulsive symptoms collected from the Yale-Brown Obsessive-Compulsive Scale were fit. Relationships between latent class membership and treatment response, sex, symptom severity, and comorbid tic disorders were tested for relationship to class membership. Results: Latent class analysis models of best fit yielded 3 classes. Classes differed only in frequency of symptom endorsement. Classes with higher symptom endorsement were associated with earlier age of onset, being male, higher Yale-Brown Obsessive-Compulsive Scale symptom severity scores, and comorbid tic disorders. There were no differences in treatment response between classes. Conclusions: These results provide support for the validity of a single underlying latent OCD construct, in addition to the distinct symptom factors identified previously via factor analyses. © 2011 Elsevier Inc. All rights reserved.
- ItemSelective attention to fearful faces during pregnancy(2012-01-18) Roos A.; Lochner C.; Kidd M.; van Honk J.; Vythilingum B.; Stein D.J.
- ItemThe validity of DSM-IV-TR criteria B and C of hair-pulling disorder (trichotillomania): Evidence from a clinical study(2011) Lochner C.; Stein D.J.; Woods D.; Pauls D.L.; Franklin M.E.; Loerke E.H.; Keuthen N.J.In both DSM-IV-TR and the ICD-10, hair-pulling disorder (trichotillomania, or TTM) is described as hair-pulling, with a rising urge or tension prior to pulling or when attempting to resist, and pleasure, relief or gratification during or after pulling. However, it has been questioned whether all patients with hair-pulling experience these other phenomena, and whether they occur with all pulling episodes. The objective of this study was to examine the DSM-IV-TR requirement of criteria B and C for a diagnosis of TTM in a sample of people with hair-pulling. A multi-site sample of adults with hair-pulling who met both DSM-IV-TR diagnostic criteria B and C (n=82, 89.13%) were compared to those who failed to satisfy both B and C (n=10, 10.87%) on a number of clinical variables. There were no differences in hair-pulling severity, levels of comorbid depressive and anxiety symptoms, number of comorbid body-focused repetitive behaviors, or impairment between those patients who did and did not meet criteria B and C. Our study does not provide convincing support for the inclusion of the current diagnostic criteria B and C for TTM in DSM-5. © 2011 Elsevier Ireland Ltd.