Fractionating impulsivity: commentary on "choice impulsivity" and "rapid-response impulsivity" articles by Hamilton and colleagues.

Comments on the original articles "Rapid-response impulsivity: Definitions, measurement issues, and clinical implications" (see record 2015-14753-004) and "Choice impulsivity: Definitions, measurement issues, and clinical implications" (see record 2015-14753-005) by Hamilton, Mitchell, et al. and Hamilton, Littlefield, et al., respectively. The present authors note that research has made important steps toward understanding impulsivity. Rapid-Response Impulsivity and Choice Impulsivity appear to be dissociable in terms of underlying neural circuitry and associated neurochemical modulation. Although various cognitive paradigms have been developed that tap these two functions, as Hamilton and colleagues correctly argue, there is a need for standardized measurements to be validated and agreed on, and for academics and clinicians to work together in order to tackle several pressing and related questions.This is the author accepted manuscript. The final version is available from the American Psychological Association via http://dx.doi.org/10.1037/per000012

Clinical correlates of tobacco smoking in OCD: A UK, case-controlled, exploratory analysis

Background: Obsessive-compulsive disorder (OCD) is a biologically heterogeneous neuropsychiatric disorder. It is associated with impulsive as well as compulsive neurocognitive mechanisms. Cigarette smoking is common among most psychiatric patients; however, OCD patients are thought to show reduced rates. OCD smokers may thus represent a relatively uncommon OCD subtype, characterised by increased impulsivity. In this study, we aim to establish the prevalence of smoking in a large, well-defined OCD cohort. We investigate whether smokers with OCD differ from non-smokers with OCD on clinical measures of behavioural impulsivity and domains of personality and temperament, including reward-dependence and novelty-seeking. Method: 183 of 200 outpatients with DSM-IV OCD were interviewed to determine smoking status. A sub-sample of 10 smokers was compared with 10 non-smokers, pair wise matched for age and gender. Patients were assessed for DSM co-morbidity, symptom profile, OCD severity, behavioural impulsivity and personality dimensions. Results: Only 10 individuals (5.46%; five males) were smokers. Compared to OCD non-smokers, OCD smokers scored significantly higher on the Barratt Impulsiveness Scale (p < 0.001). They also scored significantly higher on TCI measures of novelty seeking (p < 0.001) and reward dependence (p < 0.001) and significantly lower on measures of harm avoidance (p < 0.001). Conclusions: Tobacco smoking is rare in OCD. Significantly higher levels of behavioural impulsivity and temperamental factors associated with reward driven impulsivity are seen in OCD smokers compared to non-smokers. Tobacco smoking may indicate a possible source of neurocognitive heterogeneity in OCD

Design and characterization of a research electrohydraulic lithotripter patterned after the Dornier HM3

An electrohydraulic lithotripter has been designed that mimics the behavior of the Dornier HM3 extracorporeal shock wave lithotripter. The key mechanical and electrical properties of a clinical HM3 were measured and a design implemented to replicate these parameters. Three research lithotripters have been constructed on this design and are being used in a multi-institutional, multidisciplinary research program to determine the physical mechanisms of stone fragmentation and tissue damage in shock wave lithotripsy. The acoustic fields of the three research lithotripters and of two clinical Dornier HM3 lithotripters were measured with a PVDF membrane hydrophone. The peak positive pressure, peak negative pressure, pulse duration, and shock rise time of the focal waveforms were compared. Peak positive pressures varied from 25 MPa at a voltage setting of 12 kV to 40 MPa at 24 kV. The magnitude of the peak negative pressure varied from -7 to -12 MPa over the same voltage range. The spatial variations of the peak positive pressure and peak negative pressure were also compared. The focal region, as defined by the full width half maximum of the peak positive pressure, was 60 mm long in the axial direction and 10 mm wide in the lateral direction. The performance of the research lithotripters was found to be consistent at clinical firing rates (up to 3 Hz). The results indicated that pressure fields in the research lithotripters are equivalent to those generated by a clinical HM3 lithotripter

Cognitive dysfunction in body dysmorphic disorder: new implications for nosological systems and neurobiological models.

UNLABELLED: Introduction Body dysmorphic disorder (BDD) is a debilitating disorder, characterized by obsessions and compulsions relating specifically to perceived appearance, and which has been newly classified within the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) Obsessive-Compulsive and Related Disorders grouping. Until now, little research has been conducted into the cognitive profile of this disorder. METHODS: Participants with BDD (n=12) and participants without BDD (n=16) were tested using a computerized neurocognitive battery investigating attentional set-shifting (Intra/Extra Dimensional Set Shift Task), decision-making (Cambridge Gamble Task), motor response-inhibition (Stop-Signal Reaction Time Task), and affective processing (Affective Go-No Go Task). The groups were matched for age, IQ, and education. RESULTS: In comparison to controls, patients with BDD showed significantly impaired attentional set-shifting, abnormal decision-making, impaired response inhibition, and greater omission and commission errors on the emotional processing task. CONCLUSION: Despite the modest sample size, our results showed that individuals with BDD performed poorly compared to healthy controls on tests of cognitive flexibility, reward and motor impulsivity, and affective processing. Results from separate studies in OCD patients suggest similar cognitive dysfunction. Therefore, these findings are consistent with the reclassification of BDD alongside OCD. These data also hint at additional areas of decision-making abnormalities that might contribute specifically to the psychopathology of BDD.Academy of Medical SciencesThis is the author accepted manuscript. The final version is available from Cambridge University Press via https://doi.org/10.1017/S109285291600046

Individual obsessive-compulsive traits are associated with poorer adjustment to the easing of COVID-19 restrictions.

BACKGROUND: As COVID-19 restrictions ease, the public are expected to relinquish previously enforced safety behaviors and resume a more normal lifestyle. Despite these aims, our recent survey of 438 adults from the general population, during a temporary release of lockdown in the United Kingdom (July-November 2020), showed that 25% of the public find re-adjustment problematic. This was especially the case in those with a history of mental disorder and obsessive-compulsive (OC) traits and symptoms, including rigidity as measured by a neurocognitive test of attentional flexibility. To aid in identifying those most at risk, we performed a secondary analysis on the data to determine which specific OC traits were related to specific aspects of behavioral adjustment. METHODS: Correlational and multiple regression analyses were performed to determine associations between the eight individual personality traits constituting DSM-5 Obsessive-Compulsive Personality Disorder (OCPD), as measured by the self-rated Compulsive Personality Assessment Scale (CPAS) and a range of self-rated Post-Pandemic Adjustment Questionnaire items. RESULTS: Three items on the Post-Pandemic Adjustment Questionnaire correlated with individual CPAS items: 'General difficulties adjusting' correlated with perfectionism, preoccupation with details, over-conscientiousness and need for control; 'social avoidance' correlated with perfectionism and preoccupation with details; and 'disinfecting behaviors' correlated with preoccupation with details and miserliness (Pearson's r - all p < .001). Intriguingly, none of the adjustment items correlated significantly with self-rated rigidity. CONCLUSIONS: Several OCPD traits predict post-pandemic adjustment difficulties, but perfectionism and preoccupation-with-details showed the most robust correlations. These traits constitute a platform for the development of new screening and interventional strategies aimed at restoring public mental health and wellbeing. Cognitive rigidity may be more reliably evaluated using an objective form of assessment

Altered cognitive response to serotonin challenge as a candidate endophenotype for obsessive-compulsive disorder.

RATIONALE: Obsessive-compulsive disorder (OCD) implicates dysfunction of orbitofrontal and insula-related circuitry and of the serotonin system. There is an on-going search in psychiatry for intermediate biological markers, termed 'endophenotypes', that exist not only in patients with a given disorder but also in their clinically unaffected first-degree relatives. OBJECTIVE: Pharmacological challenge is recognized as a means of eliciting an endophenotype, but this strategy has yet to be used in OCD. METHODS: Twenty-three OCD patients without comorbidities (12 [52.2 %] female), 13 clinically asymptomatic first-degree relatives of OCD patients (11 [84.6 %] female) and 27 healthy controls (16 [59.3 %] female) received single-dose escitalopram (20 mg) and placebo in a randomized double-blind crossover design. Effects of treatment on decision-making were quantified using the Cambridge Gamble Task (CGT) in conjunction with a mixed model analysis of covariance (ANCOVA). RESULTS: There was a significant interaction between serotonergic challenge and group for risk adjustment on the CGT (F = 4.1406; p = 0.02). Only controls showed a significant placebo-drug change in risk adjustment (p = 0.02; versus p > 0.10). Numerically, escitalopram was associated with increase in risk adjustment in controls and reductions in the other groups. Change in risk adjustment was similar in OCD patients and relatives (p = 0.806) and differed significantly from controls (p = 0.007; p = 0.041, respectively). CONCLUSIONS: Individuals with OCD, and first-degree relatives, showed an altered cognitive response to serotonin challenge. This is the first demonstration of a candidate pharmacological challenge endophenotype for the disorder. Future work should confirm these findings in a larger sample size and ideally extend them to other cognitive paradigms, utilizing functional neuroimaging.This work was supported by the Medical Research Council of South Africa, the Obsessive-Compulsive Foundation (Prof Stein), the National Research Foundation of South Africa (Prof Lochner), an unrestricted grant from Lundbeck H/S and by a Starter Grant for Clinical Lecturers from the Academy of Medical Sciences UK (Dr Chamberlain).This is the author accepted manuscript. The final version is available from Springer via http://dx.doi.org/10.1007/s00213-015-4172-

Avoid jumping to conclusions under uncertainty in Obsessive Compulsive Disorder.

High levels of intolerance of uncertainty (IU) could contribute to abnormal decision making in uncertain situations. Patients with Obsessive Compulsive Disorder (OCD) often report high IU, indecisiveness and the need to seek greater certainty before making decisions. The Beads task is a commonly used task assessing the degree of information gathering prior to making a decision and so would be predicted to show impairments in OCD patients. Results to date have found mixed support for this, possibility due to methodological issues. Here, a group of OCD patients (n = 50) with no comorbidities was compared with age, gender, and verbal-IQ matched controls (n = 50) on the most commonly used version of the Beads task. An independent sample of healthy volunteers with high versus low OC symptoms, and high versus low IU were also assessed (n = 125). There was no evidence that patients with OCD differed from control volunteers in the degree of information gathering prior to making a decision. Medication status and age did not appear to mediate performance. Similarly, there were no association in healthy volunteers between task performance and OC or IU characteristics. Additional measures examining the degree of certainty initially showed support for greater uncertainty in patients, but this was due to deviations from task instructions in a subset of patients. We conclude that despite the large sample size and good matching between groups, the Beads task in its most widely used form is not a useful measure of IU or of information gathering in OCD. The results argue against a robust behavioural difference in OCD when compared to controls. Recommendations for future studies employing the task are discussed

Advances in problematic usage of the internet research - A narrative review by experts from the European network for problematic usage of the internet

Global concern about problematic usage of the internet (PUI), and its public health and societal costs, continues to grow, sharpened in focus under the privations of the COVID-19 pandemic. This narrative review reports the expert opinions of members of the largest international network of researchers on PUI in the framework of the European Cooperation in Science and Technology (COST) Action (CA 16207), on the scientific progress made and the critical knowledge gaps remaining to be filled as the term of the Action reaches its conclusion. A key advance has been achieving consensus on the clinical definition of various forms of PUI. Based on the overarching public health principles of protecting individuals and the public from harm and promoting the highest attainable standard of health, the World Health Organisation has introduced several new structured diagnoses into the ICD-11, including gambling disorder, gaming disorder, compulsive sexual behaviour disorder, and other unspecified or specified disorders due to addictive behaviours, alongside naming online activity as a diagnostic specifier. These definitions provide for the first time a sound platform for developing systematic networked research into various forms of PUI at global scale. Progress has also been made in areas such as refining and simplifying some of the available assessment instruments, clarifying the underpinning brain-based and social determinants, and building more empirically based etiological models, as a basis for therapeutic intervention, alongside public engagement initiatives. However, important gaps in our knowledge remain to be tackled. Principal among these include a better understanding of the course and evolution of the PUI-related problems, across different age groups, genders and other specific vulnerable groups, reliable methods for early identification of individuals at risk (before PUI becomes disordered), efficacious preventative and therapeutic interventions and ethical health and social policy changes that adequately safeguard human digital rights. The paper concludes with recommendations for achievable research goals, based on longitudinal analysis of a large multinational cohort co-designed with public stakeholders

Computational modelling reveals contrasting effects on reinforcement learning and cognitive flexibility in stimulant use disorder and obsessive-compulsive disorder: remediating effects of dopaminergic D2/3 receptor agents

Abstract: Rationale: Disorders of compulsivity such as stimulant use disorder (SUD) and obsessive-compulsive disorder (OCD) are characterised by deficits in behavioural flexibility, some of which have been captured using probabilistic reversal learning (PRL) paradigms. Objectives: This study used computational modelling to characterise the reinforcement learning processes underlying patterns of PRL behaviour observed in SUD and OCD and to show how the dopamine D2/3 receptor agonist pramipexole and the D2/3 antagonist amisulpride affected these responses. Methods: We applied a hierarchical Bayesian method to PRL data across three groups: individuals with SUD, OCD, and healthy controls. Participants completed three sessions where they received placebo, pramipexole, and amisulpride, in a double-blind placebo-controlled, randomised design. We compared seven models using a bridge sampling estimate of the marginal likelihood. Results: Stimulus-bound perseveration, a measure of the degree to which participants responded to the same stimulus as before irrespective of outcome, was significantly increased in SUD, but decreased in OCD, compared to controls (on placebo). Individuals with SUD also exhibited reduced reward-driven learning, whilst both the SUD and OCD groups showed increased learning from punishment (nonreward). Pramipexole and amisulpride had similar effects on the control and OCD groups; both increased punishment-driven learning. These D2/3-modulating drugs affected the SUD group differently, remediating reward-driven learning and reducing aspects of perseverative behaviour, amongst other effects. Conclusions: We provide a parsimonious computational account of how perseverative tendencies and reward- and punishment-driven learning differentially contribute to PRL in SUD and OCD. D2/3 agents modulated these processes and remediated deficits in SUD in particular, which may inform therapeutic effects

A cross sectional study of impact and clinical risk factors of antipsychotic-induced OCD.

A large proportion of schizophrenia patients treated with second generation antipsychotics will develop Obsessive Compulsive Disorder (OCD). However, there are few studies about the impact of this comorbidity and who is at higher risk. In this study of clozapine-treated patients, we aimed to determine the impact on outcome of clozapine-induced OCD, as well as the clinical and sociodemographic risk factors related to OCD-onset in clozapine patients. We had strict and novel inclusion criteria to minimise mis-identification of cases. The Obsessive-Compulsive Inventory-Revised (OCI-R) was used to divide 231 clozapine-treated patients into extreme cases of OCD (OCI  ≥ 24 or checking subscale ≥6) versus non-OCD (OCI <15 and checking subscale <4). The Global Assessment of Functioning (GAF), short version of Warwick-Edinburgh Wellbeing scale and Clinical Global Impression for schizophrenia (CGI) scales were used to determine outcome. Socio-demographic information was used to identify the risk factors for OCD development. We found that schizophrenia patients with OCD symptoms had a significantly lower patient rated wellbeing scores (p < 0.001) only (no difference in clinician rated wellbeing scores), higher CGI positive (p < 0.01) and higher CGI depressive scores (p < 0.05). The only risk factors that reached significance level were higher treatment dose (p < 0.01) and younger paternal age at birth (p < 0.05). There is scope for future studies based on e.g. imaging and genetic studies to further investigate causality, and in improving clinician screening for OCD.MB was supported by her studentship from the Mental Health Research UK. YW is supported by the Association Française du syndrome de Gilles de la Tourette, Foundation de recherche Medicale and Dystonia Foundation for Medical Research (USA). NF has held research or networking grants from the ECNP, UK NIHR, EU H2020, has accepted paid speaking engagements including travel and hospitality in industry supported symposia for Abbott, SunPharma, has accepted travel and hospitality expenses from the BAP, ECNP, RCPsych, CINP, receives payment from Taylor and Francis for editorial duties. TWR was supported by Wellcome Trust Senior Investigator Award 104631/X/14/Z. EF received intramural funding from CPFT/NIHR-CRN supported setting the database