Browsing by Author "Chamberlain, Samuel R."

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    Preventing problematic internet use during the COVID-19 pandemic : consensus guidance
    (Elsevier Inc, 2020-07) Király, Orsolya; Potenza, Marc N.; Stein, Dan J.; King, Daniel L.; Hodgins, David C.; Saunders, John B.; Griffiths, Mark D.; Gjoneska, Biljana; Billieux, Joël; Brand, Matthias; Abbott, Max W.; Chamberlain, Samuel R.; Corazza, Ornella; Burkauskas, Julius; Sales, Célia M. D.; Montag, Christian; Lochner, Christine; Grünblatt, Edna; Wegmann, Elisa; Martinotti, Giovanni; Lee, Hae Kook; Rumpf, Hans-Jürgen; Castro-Calvo, Jesús; Rahimi-Movaghar, Afarin; Higuchi, Susumu; Menchon, Jose M.; Zohar, Joseph; Pellegrini, Luca; Walitza, Susanne; Fineberg, Naomi A.; Demetrovics, Zsolt
    As a response to the COVID-19 pandemic, many governments have introduced steps such as spatial distancing and "staying at home" to curb its spread and impact. The fear resulting from the disease, the 'lockdown' situation, high levels of uncertainty regarding the future, and financial insecurity raise the level of stress, anxiety, and depression experienced by people all around the world. Psychoactive substances and other reinforcing behaviors (e.g., gambling, video gaming, watching pornography) are often used to reduce stress and anxiety and/or to alleviate depressed mood. The tendency to use such substances and engage in such behaviors in an excessive manner as putative coping strategies in crises like the COVID-19 pandemic is considerable. Moreover, the importance of information and communications technology (ICT) is even higher in the present crisis than usual. ICT has been crucial in keeping parts of the economy going, allowing large groups of people to work and study from home, enhancing social connectedness, providing greatly needed entertainment, etc. Although for the vast majority ICT use is adaptive and should not be pathologized, a subgroup of vulnerable individuals are at risk of developing problematic usage patterns. The present consensus guidance discusses these risks and makes some practical recommendations that may help diminish them.
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    Problematic use of the Internet is a unidimensional quasi-trait with impulsive and compulsive subtypes
    (BMC (part of Springer Nature), 2019-11-08) Tiego, Jeggan; Lochner, Christine; Ioannidis, Konstantinos; Brand, Matthias; Stein, Dan J.; Yucel, Murat; Grant, Jon E.; Chamberlain, Samuel R.
    Background: Problematic use of the Internet has been highlighted as needing further study by international bodies, including the European Union and American Psychiatric Association. Knowledge regarding the optimal classification of problematic use of the Internet, subtypes, and associations with clinical disorders has been hindered by reliance on measurement instruments characterized by limited psychometric properties and external validation. Methods: Non-treatment seeking individuals were recruited from the community of Stellenbosch, South Africa (N = 1661), and Chicago, United States of America (N = 827). Participants completed an online version of the Internet Addiction Test, a widely used measure of problematic use of the Internet consisting of 20-items, measured on a 5-point Likert-scale. The online questions also included demographic measures, time spent engaging in different online activities, and clinical scales. The psychometric properties of the Internet Addiction Test, and potential problematic use of the Internet subtypes, were characterized using factor analysis and latent class analysis. Results: Internet Addiction Test data were optimally conceptualized as unidimensional. Latent class analysis identified two groups: those essentially free from Internet use problems, and those with problematic use of the Internet situated along a unidimensional spectrum. Internet Addiction Test scores clearly differentiated these groups, but with different optimal cut-offs at each site. In the larger Stellenbosch dataset, there was evidence for two subtypes of problematic use of the Internet that differed in severity: a lower severity “impulsive” subtype (linked with attention-deficit hyperactivity disorder), and a higher severity “compulsive” subtype (linked with obsessive-compulsive personality traits). Conclusions: Problematic use of the Internet as measured by the Internet Addiction Test reflects a quasi-trait - a unipolar dimension in which most variance is restricted to a subset of people with problems regulating Internet use. There was no evidence for subtypes based on the type of online activities engaged in, which increased similarly with overall severity of Internet use problems. Measures of comorbid psychiatric symptoms, along with impulsivity, and compulsivity, appear valuable for differentiating clinical subtypes and could be included in the development of new instruments for assessing the presence and severity of Internet use problems.
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    Striatal abnormalities in trichotillomania : a multi-site MRI analysis
    (Elsevier, 2019) Isobe, Masanori; Redden, Sarah A.; Keuthen, Nancy J.; Stein, Dan J.; Lochner, Christine; Grant, Jon E.; Chamberlain, Samuel R.
    Trichotillomania (hair-pulling disorder) is characterized by the repetitive pulling out of one's own hair, and is classified as an Obsessive-Compulsive Related Disorder. Abnormalities of the ventral and dorsal striatum have been implicated in disease models of trichotillomania, based on translational research, but direct evidence is lacking. The aim of this study was to elucidate subcortical morphometric abnormalities, including localized curvature changes, in trichotillomania. De-identified MRI scans were pooled by contacting authors of previous peer-reviewed studies that examined brain structure in adult patients with trichotillomania, following an extensive literature search. Group differences on subcortical volumes of interest were explored (t-tests) and localized differences in subcortical structure morphology were quantified using permutation testing. The pooled sample comprised N= 68 individuals with trichotillomania and N =41 healthy controls. Groups were wellmatched in terms of age, gender, and educational levels. Significant volumetric reductions were found in trichotillomania patients versus controls in right amygdala and left putamen. Localized shape deformities were found in bilateral nucleus accumbens, bilateral amygdala, right caudate and right putamen. Structural abnormalities of subcortical regions involved in affect regulation, inhibitory control, and habit generation, play a key role in the pathophysiology of trichotillomania. Trichotillomania may constitute a useful model through which to better understand other compulsive symptoms. These findings may account for why certain medications appear effective for trichotillomania, namely those modulating subcortical dopamine and glutamatergic function. Future work should study the state versus trait nature of these changes, and the impact of treatment.