This study aims to investigate the acute and chronic effects of a dietary intervention of 22 g freeze-dried whole wild blueberry powder. https://doi.org/10.1371/journal.pone.0205154.s001, https://doi.org/10.1371/journal.pone.0205154.s002, https://doi.org/10.1371/journal.pone.0205154.s003, https://doi.org/10.1371/journal.pone.0205154.s004. Stroebe for her helpful comments and suggestions. Therefore, the current study included both depression-relevant and threat-related stimuli to test whether participants with a clinically-diagnosed MDD show an AB not only for depression-related stimuli but also for threat-related stimuli. The total score of the IDS-SR was used as an index for the severity of depression. In other words, anxious individuals seemed to have an attentional bias towards negative information, leading them to become distracted by such images, whereas depressed and healthy participants were not. Formal analysis, The relatively slow reaction times on validly cued trials indicate an inhibition of return effect. Roles Stimuli were presented on a black background. Resources, here. The aims of attentional bias modification is to reduce anxiety by attenuating bias towards threatening information. Most important, the findings of this simulation study indicated that TL-BS indices are prone to result in false positive group differences; the differences between groups might in fact reflect differences in mean reaction times and/ or differences in overall SD . https://doi.org/10.1371/journal.pone.0205154.t003. Relatively strong cue validity effects and relatively weak IoR (and thus more positive or less negative AB scores) are interpreted as attention bias toward a particular stimulus type, whereas relatively weak cue validity effects and strong IoR (and thus less positive or more negative AB scores) are considered to reflect a bias away from particular stimuli. were more revealing of attentional bias than were emotional words and scene images . Because indices were positively skewed, variables were subjected to a square root transformation, before being used in the analyses. The between subject tests indicated that the multivariate effect of group was mainly carried by the AB index of negative adjectives specifically for long duration trials (1250 ms). In sum, this study employed both traditional and recently proposed dynamic indices of AB to examine (i) the stimulus specificity and (ii) temporal unfolding of AB in MDD, (iii) whether the pattern of AB varies between MDD participants with and without a comorbid AD, (iv) whether AB is still present in participants who are recovered from MDD. This study found no consistent evidence for AB towards negative adjectives or away from positive adjectives in strictly defined clinical groups of MDD participants with or without a comorbid AD. Researchers have found that people who have eating disorders tend to pay more attention to stimuli related to food, while individuals experiencing drug addictions tend to be hypersensitive to drug-related cues.1 For people struggling to recover from an eating disorder or addiction, this tendency to pay attention to certain signals while discounting others c… We considered indices deviating more than 3 SDs from the mean of the group as outliers for all the groups. There is also evidence that depression is characterized by a lack of attention towards positive information. The MDD group (mean difference 0.48 (s.e. We computed separate indices of AB for each of the presentation times (500 and 1250 ms). Copyright © 2020 Elsevier B.V. or its licensors or contributors. than never depressed individuals . Unexpectedly, the group of remitted participants also showed evidence for a threat bias as indexed by heightened variability in AB for general threat words (1250 ms trials). To test the predicted pattern of stimulus specific AB as a function of group we subjected the traditional AB scores (Negative 500 ms, Negative 1250 ms, Positive 500 ms, Positive 1250 ms, Threat 500 ms, Threat 1250 ms) to a Multivariate Analyses of Variance (MANOVA) with the AB scores as the dependent factor and Group (Comparison, rMDD, MDD, and MDD/AD) as fixed factor. If a stimulus (a “cue”) precedes the target at the same spatial location, it is called a “valid” trial. 3.35), p = .04, 95% CI [0.20, 17.93], d = 0.20) (see also Table 4 for all significant between group contrasts). At shorter presentation times of the cues (100–300 ms), faster responding is generally found on validly cued trials compared to invalidly cued trials, a finding that is referred to as the “cue validity” or cue facilitation effect. As such, a given trial was included in maximally two pairs maximum. Table 6 gives a detailed description of the TL-BS indices Mean and Variability scores per stimulus type and presentation time. Data curation, The lifetime Composite International Diagnostic Interview (CIDI, lifetime version 2.1;) was used to diagnose anxiety (panic disorder with agoraphobia, panic disorder without agoraphobia, agoraphobia without panic disorder, social phobia, generalized anxiety disorder) and depressive disorders according to DSM-IV criteria . Per presentation time and per stimulus type (e.g., positive), we calculated for each participant (i) the mean TL-BS Towards (the mean of the TL-BS scores that were higher than 0 ms indicating attention towards the stimuli [i.e., invalid trial RT was higher than valid trial RT]), (ii) mean TL-BS Away (the mean of the TL-BS scores that were lower than 0 indicating attention away from the stimuli [i.e., valid trial RT was higher than invalid trial RT]), (iii) the peak TL-BS Towards (maximum TL-BS indicating an AB toward target stimuli [i.e., invalid trial RT was higher than valid trial RT]), (iv) peak TL-BS Away (minimum TL-BS indicating attention away from target stimuli [i.e., valid trial RT was higher than invalid trial RT]), and (v) variability (reflects the degree of stability or temporal variability in the expression of attention toward and/or away over time, calculated by the standard deviation of TL-BS). rMDD individuals also attended to anxiety-related images (e.g., scenes of threat and injury, people being threatened by weapons) more than never depressed individuals. At baseline, a total of 748 (25.1% of the total sample) respondents were using antidepressants . Participants were asked to focus their attention on the fixation cross and to respond as quickly and correctly as possible by pressing the left key of a response box when the target was presented on the left side or by pressing the right key of the response box when the target was presented on the right side. See S1 Appendix for the stimulus words per stimulus type. Given the stimulus onset asynchrony used in the current study (500 and 1250 ms), negative cue validity effects were to be expected. Data curation, In this study, we tested the robustness of these earlier findings by comparing a large group of rMDD to never-depressed individuals with regard to their AB for positive and negative adjectives, as well as for general threat words. Yet, a recent analogue study showed that participants who reported both symptoms of anxiety and depression displayed an AB for emotional words, whereas participants who only reported heightened symptoms of depression did not . Even if there is an initial improvement in response to treatment, this is often followed by relapse, with an increasing risk of relapse after every depressive episode . The threatening and neutral words were selected from earlier studies on AB [45, 46]. Thus, heightened AB for negative or a lowered AB for positive adjectives seems not to be critically involved in the maintenance of MDD. We computed an AB score for negative, threat, and positive words per presentation time. 8.48), p = .99, 95% CI [-18.51; 21.99], d = 0.04) nor the rMDD group (mean difference 1.44 ms (s.e. The target was presented until a response was made. Importantly, previously depressed individuals spent more time looking at anxiety-relevant images during a free-viewing task (such as scenes of people being threatened with weapons, people with physical injuries, dangerous situations) than never depressed individuals . 0.23), p < .001, 95% CI [0.26, 1.48], d = 0.44 (see also Table 4). However, since most evidence is based on analogue research or small heterogeneous clinical samples (e.g., , it remains important to test the robustness of this pattern in well-defined clinical samples. Interestingly, the results of this re-analysis showed that rMDD participants were characterized by higher levels of TL-BS, specifically increased variability, than non-depressed individuals. e0205154. General exclusion criteria were presence of a psychiatric disorder other than depressive or AD (e.g., psychosis, bipolar disorder, severe addictive disorder) or lack of fluency in Dutch. The findings of the TL-BS should however be interpreted with care. However, this does not seem to be a very convincing explanation, since the mixed group that was included in the current design did not show an AB for negative adjectives either. The between subject tests indicated that for the negative adjectives none of the TL-BS scores showed a significant difference between groups (Negative Away 500 ms F (3,734) = 1.20, p = .30, partial η2 = .005; Negative Towards 1250 ms F (3,734) = 1.68, p = .16, partial η2 = .007, and Negative Away 1250 ms F (3,734) = 1.15, p = .32, partial η2 = .005), though for Negative Towards 500 ms this just fell short of the conventional level of significance (Negative Towards 500 ms F (3,734) = 2.38, p = .06, partial η2 = .01). This is known as the inhibition of return effect (IoR;). These other measurements are beyond the scope of this study (see [34, 35]for a detailed description). The two-year follow-up assessment consisted of a face-to-face clinic visit, in which baseline assessments–except those concerning stable concepts–were repeated. Table 4 shows the significant post hoc contrasts for the analyses of the traditional AB scores as well as of the TL-BS indices. Bonferroni adjusted post hoc tests indicated that for TL-BS Variability Neutral 500 ms none of the groups differences were significant. Non-response was considered a missing value and was discarded. They were asked to ignore any other information that would be presented. Below we discuss these findings in relation to the key issues that this study aimed to address. Thus, although our findings did not provide straightforward support for the usefulness of TL-BS as an index of the temporal dynamics in AB that might have superior power over traditional AB indices on negative adjectives to differentiate between groups, it cannot be seen as a critical challenge to the relevance of indices that take temporal dynamics into account. Writing – review & editing, Affiliation Keywords: Attentional bias modification, Depression, Clinical trial Background A wide range of treatments are available for depression. For more information about PLOS Subject Areas, click  did (sum of all distances between sequential TL-BSs divided by the number of TL-BSs). Yet, the current findings did provide evidence for the predicted AB for general threat words in the mixed group of MDD with AD(s) as indexed by trial-level AB scores, whereas for the traditional AB index, the specific contrast between the mixed MDD/ADD group and the comparison group only showed a non-significant tendency suggesting that specifically for the short duration trials (500 ms) the mixed group showed a heightened (less negative) bias score. To test whether differences in AB would be most pronounced when stimuli would be presented for a longer duration as was found in previous analogue research (e.g., ), we also included trials with 1250 ms presentation time. Of the 2981 participants who were included at baseline, 2596 respondents participated in the 2-year follow-up measurements. We thank Martine Ruiter for her helpful ideas and for her assistance in the initial process of data-reduction and especially Prof. M.S. Software, This is a Veteran's Administration Career Development Award 2 proposal for Colleen Mills-Finnerty, Ph.D., entitled ?Causal brain mechanisms of value-based attentional capture in depression.? This pattern indicates that for both presentation times the mixed MDD/AD group showed more variability in AB for general threat words than the comparison group, whereas the rMDD group also showed more variability in AB for general threat words than the comparison group but only for short duration trials (500 ms). Because these processes might play a different role in MDD, it would be interesting in future research to use a task that is especially designed for this (e.g., the Attentional Response to Distal vs. Proximal Emotional Information) . 0.25), p < .01, 95% CI [0.29, 1.65], d = 0.31. It is possible that other results would have emerged if we had used shorter or longer presentation times. Less negative AB scores were indicative of a weaker inhibition of return effect (see ). Moreover, the traditional AB-index reflects differential responding to emotional versus neutral cue words, whereas the current TL-BS indices reflect differential responding to validly and invalidly cued trials for each of the cue word types separately. Apart from the conceptual criticisms with regard to TL-BS (e.g.,), it is important to note that we measured AB with an ECT instead of a visual probe task (VPT), and used four instead of three categories of stimuli (as[30, 31]). The study protocol was approved centrally by the Ethical Review Board of the VU University Medical Centre (protocol number 2013/183) and subsequently by local review boards of each participating centre (IRBs of the VU University Medical Center, the University Medical Center Groningen and the Leiden University Medical Center). Data curation, Many of these cognitive models include attentional bias (AB) as both a contributing and a maintaining factor to depression (e.g.,. This attention bias of information processing plays a crucial role in the pathogenesis, maintenance, and development of depression (11, 12). The traditional AB scores were calculated using the formula suggested by Mogg et al.,: Attentional bias score (AB score) = (median RT invalid emotional cue–median RT valid emotional cue)–(median RT invalid neutral cue–median RT valid neutral cue). The notion is that by practicing attending to happiness, I recognizing that the tendency to focus on the negative can lead to depression, and deliberately seeking out positive stimuli in the environment, we may be able to treat and/or prevent depression. However, systematic reviews point to limited efficacy in terms of remission, response rates and long-term effects for both pharmacological  … In addition, we hypothesized that the group of remitted participants would still have an AB, but less than the clinical groups (participants with MDD with and without ADs). In this way we were able to examine whether the pattern of AB in pure MDD participants differed from that in individuals with comorbid AD. The aim of this study was to improve our understanding of the underlying mechanisms in the maintenance of depression. The current study also failed to corroborate the findings of an earlier small-scale visual probe study (using 500 ms presentation time) among individuals with dysthymia (n = 13) or MDD (n = 7) indicating that these participants were characterized by a vigilance for adjectives that were very similar to the ones used in the current study (e.g., inadequate, useless, stupid, inept) . One explanation could be that the current MDD group consisted of people without a comorbid (or history of) AD, whereas in the previous research, selection of participants was less stringent. Whether Obsessive Compulsive Disorder (OCD) is associated with an increased attentional bias to emotive stimuli remains controversial. here. Validation, According to the cognitive model of depression, patients with depression exhibit a negative attentional bias that is manifested by their prioritization of negative cognitive stimuli. Writing – review & editing, Affiliation Method. Data Availability: According to European law (AVG) data contain potentially identifying or sensitive patient information are restricted; our data involving clinical participants are not freely available in the manuscript, supplemental files, or in a public repository. In this way, we computed time series of TL-BS per participant. In total, the task consisted of 4 stimulus types x 16 exemplars x 2 valid/invalid x 2 presentation times = 256 word trials, 10 practice trials and 20 digit trials. 0.21), p < .001, 95% CI [0.23; 1.27], d = 0.40. A meta-analysis by Bar-Haim et al. ), this AB may reflect a heightened sensitivity for negative adjectives. This has limited the amount of data points to express TL-BS and the number of different trial types tripled, which could both have influenced the reliability and validity of these indices in our study. All in all, the findings do not corroborate the view that an AB towards negative or away from positive adjectives is critically involved in currently depressed individuals. Attentional bias to negative information has been considered as a vulnerability factor for depression, enhancing susceptibility and maintenance of this disorder. Department of Clinical Psychology & Experimental Psychopathology, University of Groningen, Groningen, the Netherlands, Roles Participants were recruited from the general population, through general practitioners, and in mental health care institutions, and included: healthy individuals with no history of psychiatric disorders, individuals at risk because of prior episodes, sub-threshold symptoms or family history, and individuals with a current first or recurrent MDD or AD.
2020 attentional bias depression