Performance Monitoring in Depression: Behavioural and Neurophysiological Correlates of Feedback Processing

Unipolar major depressive disorder (MDD) is a common mental health disorder which has a lifetime prevalence of about 19% in the Netherlands (De Graaf et al., 2010). This means that almost 1 out of 5 persons will experience a depressive episode at some point in their lives. Women are almost twice as often affected as men (Bijl et al., 1997, De Graaf et al., 2010). Worldwide, about 121 million of people are affected by depression, and it is one of the leading causes of disability (WHO, 2011)

Brain responses and approach bias to social alcohol cues and their association with drinking in a social setting in young adult males

Alcohol is mainly consumed in social settings, in which people often adapt their drinking behaviour to that of others, also called imitation of drinking. Yet, it remains unclear what drives this drinking in a social setting. In this study, we expected to see stronger brain and behavioural responses to social compared to non-social alcohol cues, and these responses to be associated with drinking in a social setting. The sample consisted of 153 beer-drinking males, aged 18–25 years. Brain responses to social alcohol cues were measured during an alcohol cue-exposure task performed in an fMRI scanner. Behavioural responses to social alcohol cues were measured using a stimulus-response compatibility task, providing an index of approach bias towards these cues. Drinking in a social setting was measured in a laboratory mimicking a bar environment. Specific brain responses to social alcohol cues were observed in the bilateral superior temporal sulcus and the left inferior parietal lobe. There was no approach bias towards social alcohol cues specifically; however, we did find an approach bias towards alcohol (versus soda) cues in general. Brain responses and approach bias towards social alcohol cues were unrelated and not associated with actual drinking. Thus, we found no support for a relation between drinking in a social setting on the one hand, and brain cue-reactivity or behavioural approach biases to social alcohol cues on the other hand. This suggests that, in contrast to our hypothesis, drinking in a social setting may not be driven by brain or behavioural responses to social alcohol cues

Planning to make economic decisions in the future, but choosing impulsively now: Are preference reversals related to symptoms of ADHD and depression?

A preference for smaller immediate rewards over larger delayed rewards (delay discounting, DD) is common in attention deficit hyperactivity disorder (ADHD), but rarely investigated in depression. Whether this preference is due to sensitivity to reward immediacy or delay aversion remains unclear. To investigate this, we examined whether ADHD and depressive symptoms are associated with preference reversals: a switch from smaller immediate rewards to larger delayed rewards when smaller rewards are also delayed. We also examined whether these symptoms differentially affect DD of losses. In Study 1 undergraduates completed a questionnaire about ADHD symptoms, and performed a hypothetical DD task. In the NOW condition, participants were presented with choices between a small reward available today and a large reward available after one year. In the FUTURE condition both rewards were delayed with +1 year. In Study 2 undergraduates completed questionnaires about ADHD and depressive symptoms and performed a DD task with gains and losses. Participants showed preference reversals in both studies and tasks. Losses were less steeply discounted than gains. ADHD and depressive symptoms did not influence these effects. Depressive symptoms, but not ADHD symptoms, were associated with less economic choices in general. These findings suggest that impulsive choice in depression is not explained by sensitivity to reward immediacy

Quick Delay Questionnaire: Reliability, validity, and relations to functional impairments in adults with attention-deficit/hyperactivity disorder (ADHD)

Item does not contain fulltextThe Quick Delay Questionnaire (QDQ) is a self-report measure of delay-related behaviors in adults, and the present study aimed at investigating the psychometric properties of QDQ scores, how well they can discriminate between ADHD adults and both clinical and nonclinical controls, as well as their relations to measures of functional impairments. In the present study, QDQ ratings, a laboratory measure of delay discounting, and ratings of functional impairments were collected from adults diagnosed with attention-deficit/hyperactivity disorder (ADHD; n = 51), a clinical control group with other psychiatric disorders (n = 46), and a nonclinical control group (n = 105). Results showed that the QDQ scores showed adequate reliability. Adults with ADHD had higher scores compared with normal controls on both QDQ subscales, and they also reported higher levels of delay aversion than the clinical controls. Logistic regression analyses showed high specificity but low sensitivity when trying to discriminate between adults with ADHD and nonclinical controls. QDQ scores were not associated with a laboratory measure of delay discounting, but with functional impairments such as substance use, criminality, and money management. Our findings indicate that QDQ scores are reliable, but this instrument should be regarded as a complement rather than as a replacement for laboratory measures. The relatively low sensitivity of QDQ scores is in line with current models of heterogeneity stating that only a subgroup of individuals with ADHD has high levels of delay-related behaviors. Our findings further indicate that this subgroup may be at particularly high risk for problems in everyday life.12 p

Waiting and working for rewards: Attention-Deficit/Hyperactivity Disorder is associated with steeper delay discounting linked to amygdala activation, but not with steeper effort discounting

Item does not contain fulltextObjective: Children and adolescents with ADHD have a relatively strong preference for smaller immediate rewards over larger delayed rewards (steep delay discounting). It is unknown whether such steep discounting of rewards is specific for delayed rewards, i.e., supporting the delay aversion account of ADHD, or whether it is also present for effortful rewards, i.e., representing general reward insensitivity. Therefore, this study examined behavioral and BOLD responses during delay discounting (DD) and effort discounting (ED) in ADHD. Method: Thirty adolescents with ADHD and 28 controls (12-17 years) were scanned while performing a DD-ED task (fMRI findings were based on 21 and 25 participants, respectively). During DD, participants were presented with a series of choices between a small reward delivered immediately and a larger reward delivered after 5-25s. During ED, participants were presented with choices between a small reward that was delivered after exerting 15% of their maximal hand grip strength and a larger reward delivered after exerting 30-90% of their strength. Results: Analyses on the subjective values of delayed and effortful rewards and on the Area Under the discounting Curves (AUCs) indicated that adolescents with ADHD showed steeper discounting than controls for DD, but not for ED. This was accompanied by a slightly stronger delay dose-response relationship in the amygdala for adolescents with ADHD who reported to be more delay averse in daily life. Conclusion: Together, these results - steeper DD in the ADHD group and a stronger delay dose-response relationship in the amygdala, while no evidence for group differences in ED was found - support the delay aversion account of ADHD.10 p

Writing Chinese Characters: Right or Left? : The Chinese Discriminatory Policy of Left-Handedness Correction in Terms of Handwriting

Chinese left-handed are found to be very few, especially in terms of handwriting. The Chinese educational policy that fully entitles teachers in primary school to change the left-handed students to write with their right-hand, by nudging and even force, is found to be mainly blamed as the main cause. The thesis is to raise the ethical discussion and define this policy as being discriminatory against the left-handed by checking the features, definition and identification of discrimination, and reasons forming and supporting such a discriminatory policy will be taken into the major consideration as the source of discrimination. Therefore, the thesis is to propose solutions to help with the abolishment of the policy and the elimination of the prejudicial attitudes toward the left-handed, especially in terms of writing. The thesis itself, due to the limit of previous research and scientific support, has its own blindness or disadvantage, however, such a work could be helpful with the later discussion

The prevalence of food addiction in a large sample of adolescents and its association with addictive substances

Item does not contain fulltextThe prevalence of overweight and obesity is increasing, due to, among other factors, increased availability of highly palatable food (food high in fat, salt and/or sugar). It has been proposed that certain foods and/or eating behaviours may be addictive, to a degree comparable to substances of abuse. The Yale Food Addiction Scale (YFAS) measures 'food addiction' by translating the diagnostic criteria for substance use disorder to eating behaviour. So far, only a few studies have examined the prevalence of food addiction in children with the YFAS for children (YFAS-C). Large-scale studies, especially among adolescents, are lacking. Adolescence is of particular interest because it is a period wherein unhealthy eating behaviours or addictive tendencies are likely to develop. The current study examines the prevalence of food addiction using the YFAS-C in a large group of Dutch adolescents (N = 2653) aged 14-21 years. With Generalized Estimation Equation (GEE) analysis we tested the relationship between food addiction symptoms and smoking, cannabis use, alcohol use, and sugar intake through drinks, while controlling for gender, age, educational level and weight class. In the total sample 2.6% met the criteria for a food addiction 'diagnosis', and the average symptom count was 1.0 (SD = 1.3, range 0-7). Symptoms of food addiction were positively associated with smoking, alcohol use, cannabis use and sugar intake. We propose that future studies focus on possible genetic/(neuro)biological mechanisms involved in both food addiction and substance use and that longitudinal designs are needed to examine possible causal pathways.9 p

Brain responses and approach bias to social alcohol cues and their association with drinking in a social setting in young adult males

Alcohol is mainly consumed in social settings, in which people often adapt their drinking behavior to that of others, also called imitation of drinking. Yet, it remains unclear what drives this drinking in a social setting. In this study, we expected to see stronger brain and behavioral responses to social compared to non-social alcohol cues, that would be associated with drinking in a social setting. The sample consisted of 153 beer-drinking males, aged 18-25 years. Brain responses to social alcohol cues were measured during an alcohol cue exposure task in the scanner. Behavioral responses to social alcohol cues were measured using a stimulus-response compatibility task, providing an index of approach bias towards these cues. Drinking in a social setting was measured in a laboratory mimicking a bar environment. Specific brain responses to social alcohol cues were observed in the bilateral superior temporal sulcus and the left inferior parietal lobe. There was no approach bias towards social alcohol cues specifically, however, we did find an approach bias towards alcohol (versus soda) cues in general. Brain responses and approach bias towards social alcohol cues were unrelated and not associated with actual drinking. Thus, we found no support for a relation between drinking in a social setting on the one hand, and brain cue-reactivity or behavioral approach biases to social alcohol cues on the other hand. This suggests that, in contrast to our hypothesis, drinking in a social setting may not be driven by brain or behavioral responses to social alcohol cues

Acute tryptophan depletion in healthy males attenuates phasic cardiac slowing but does not affect electro-cortical response to negative feedback

Item does not contain fulltextRationale: Recent studies have shown that serotonin might be involved in performance monitoring, although the results have been inconclusive. Inconsistent results might be related to the type of pharmacological manipulation and the used behavioral and physiological measures. Objectives: The present study aimed at further specifying the role of serotonin in performance monitoring. Materials and methods: The effect of serotonin on performance monitoring was studied by using acute tryptophan depletion (ATD), a well-known method to transiently lower central serotonin levels. Twenty healthy male volunteers performed a time-estimation task and their event-related brain potential (ERP), behavioral, and cardiac responses to feedback stimuli were measured. Furthermore, subjective mood and amino-acid levels were determined. Results: As expected, ATD did not affect mood and lowered tryptophan levels. ATD attenuated cardiac slowing to negative feedback but did not affect responses to positive feedback, ERPs, and performance measures. Conclusions: The data point in the direction of a dissociation between cardiac and electro-cortical responses. Cardiac responses appear to be more sensitive to changes in serotonin metabolism and appear to reflect different aspects of the feedback stimulus. The phasic cardiac response appears to be an important measure that provides additional information about the impact of feedback stimuli and serotonergic functioning.9 p

Does an attention bias to appetitive and aversive words modulate interference control in youth with ADHD?

Interference control refers to the ability to selectively attend to certain information while ignoring distracting information. This ability can vary as a function of distractor relevance. Distractors that are particularly relevant to an individual may attract more attention than less relevant distractors. This is referred to as attention bias. Weak interference control and altered reward sensitivity are both important features of attention deficit hyperactivity disorder (ADHD). However, interference control is typically studied in isolation. This study integrates both. Youths (aged 9 to 17 years) with ADHD (n = 37, 25 boys) and typically-developing controls (n = 38, 20 boys) completed a Stroop task using appetitive words and matched neutral words to assess whether appetitive distractors diminished interference control more in youths with ADHD than controls. In order to test for specificity, aversive words were also included. As expected, appetitive words disrupted interference control but this effect was not stronger for youths with ADHD than the controls. Aversive words, on the other hand, facilitated interference control. Dimensional analyses revealed that this facilitation effect increased substantially as a function of ADHD symptom severity. Possible mechanisms for this effect include up-regulation of interference control as a function of induced negative mood, or as a function of increased effort. In conclusion, appetitive words do not lead to worse interference control in youths with ADHD compared with controls. Interference control was modulated in a valence-specific manner, concurrent with mood-induced effects on cognitive control