Anhedonia as a transdiagnostic symptom across psychological disorders: a network approach.

BACKGROUND: Anhedonia is apparent in different mental disorders and is suggested to be related to dysfunctions in the reward system and/or affect regulation. It may hence be a common underlying feature associated with symptom severity of mental disorders. METHODS: We constructed a cross-sectional graphical Least Absolute Shrinkage and Selection Operator (LASSO) network and a relative importance network to estimate the relationships between anhedonia severity and the severity of symptom clusters of major depressive disorder (MDD), anxiety sensitivity (AS), attention-deficit hyperactivity disorder (ADHD), and autism spectrum disorder (ASD) in a sample of Dutch adult psychiatric patients (N = 557). RESULTS: Both these networks revealed anhedonia severity and depression symptom severity as central to the network. Results suggest that anhedonia severity may be predictive of the severity of symptom clusters of MDD, AS, ADHD, and ASD. MDD symptom severity may be predictive of AS and ADHD symptom severity. CONCLUSIONS: The results suggest that anhedonia may serve as a common underlying transdiagnostic psychopathology feature, predictive of the severity of symptom clusters of depression, AS, ADHD, and ASD. Thus, anhedonia may be associated with the high comorbidity between these symptom clusters and disorders. If our results will be replicated in future studies, it is recommended for clinicians to be more vigilant about screening for anhedonia and/or depression severity in individuals diagnosed with an anxiety disorder, ADHD and/or ASD.

Attentional bias, craving and cannabis use in an inpatient sample of adolescents and young adults diagnosed with cannabis use disorder: The moderating role of cognitive control.

Motivational processes like attentional bias and craving have been related to substance use. However, results are inconclusive. The present cross-sectional study was designed to replicate and extend previous research by investigating the relationships between attentional bias, craving, cognitive control and (severity of) cannabis use in a sample of inpatient adolescents and young adults (aged 18-30) diagnosed with CUD according to DSM-5. Contrary to expectations, our sample did not show attentional bias for cannabis words, neither did attentional bias correlate with craving, cognitive control or (severity of) cannabis use. In line with our hypotheses, however, increased session-induced craving was correlated to more daily cannabis use and reduced cognitive control. Furthermore, participants who displayed reduced cognitive control used more cannabis per day. A bootstrapped hierarchical regression model showed that, contrary to expectations, cognitive control did not modulate the relationships between attentional bias, craving and cannabis use. This study highlights the unique role of craving in relation to cannabis use and extends previous findings that cognitive control appears to have no moderating role regarding cannabis use disorder. Based on our results, it might well be that the underlying mechanisms of cannabis use disorder differ from those in other substance use disorders.

Selective attention and fear of cancer recurrence in breast cancer survivors.

BACKGROUND: Anxious people show an attentional bias towards threatening information. PURPOSE: It was investigated whether an attentional bias exists for cancer-related stimuli in breast cancer survivors and if different levels of fear of cancer recurrence would lead to different patterns of selective attention. METHODS: Breast cancer survivors with high (n = 35) and low (n = 32) fear of cancer recurrence were compared to 40 healthy female hospital employees. Specificity of attentional biases was investigated using a modified Emotional Stroop Task. Self-report measures were used to assess depression and anxiety, feelings of fatigue, and experienced traumas. RESULTS: Compared to control participants, breast cancer survivors with both high and low levels of fear of cancer recurrence showed increased interference for cancer-related words, but not for other word types. CONCLUSIONS: The findings suggest a specific attentional bias for cancer-related words in breast cancer survivors that is independent of level of fear of cancer recurrence.

Psychometric properties of reaction time based experimental paradigms measuring anxiety-related information-processing biases in children.

Theoretical frameworks highlight the importance of threat-related information-processing biases for understanding the emergence of anxiety in childhood. The psychometric properties of several tasks measuring these biases and their associations with anxiety were examined in an unselected sample of 9-year-old children (N=155). In each task, threat bias was assessed using bias scores reflecting task performance on threat versus non-threat conditions. Reliability was assessed using split-half and test-retest correlations of mean reaction times (RTs), accuracy and bias indices. Convergence between measures was also examined. Mean RTs showed substantial split-half and test-retest correlations. Bias score reliability coefficients were near zero and non-significant, suggesting poor reliability in children of this age. Additionally, associations between bias scores and anxiety were weak and inconsistent and performance between tasks showed little convergence. Bias scores from RT based paradigms in the current study lacked adequate psychometric properties for measuring individual differences in anxiety-related information-processing in children.

Anticipation of Social Interaction Changes Implicit Approach-Avoidance Behavior of Socially Anxious Individuals.

Earlier research has revealed implicit avoidance of social stimuli in social anxiety (SA). This study investigated such reactions in anticipation of social interaction. High (n = 24) and low (n = 22) SA females were assessed in anticipation of a getting-acquainted conversation (anticipation) and in a no-conversation-expected (neutral) condition. The Face-Turn Approach Avoidance Task was used in which participants responded to profiles of human faces or control stimuli by either pulling (approach) or pushing (avoidance) a joystick. Upon pulling, the stimuli turned toward the participant, while they turned away upon pushing. The results demonstrated the expected decreased approach response to faces in the neutral condition for the high SAs compared to the low SAs group. Unexpectedly, in the anticipation condition the high SAs showed increased approach tendencies to faces whereas, the low SAs demonstrated a decreased approach response. The implicit social approach response of the high SAs in the anticipation condition is discussed.

Relatively strong automatic appetitive action-tendencies in male carriers of the OPRM1 G-allele.

This study investigated whether automatic approach action tendencies for alcohol-related stimuli were associated with variation in the mu-opioid receptor gene (OPRM1), previously related to rewarding effects of alcohol and craving. An adapted approach avoidance task was used, in which participants pulled or pushed a joystick in reaction to the format of a picture shown on the computer screen (e.g. pull landscape pictures and push portrait pictures). Picture size on the screen changed upon joystick movement, so that upon a pull movement picture size increased (creating a sense of approach) and upon a push movement picture size decreased (avoidance). Participants reacted to four categories of pictures: alcohol-related, other appetitive, general positive and general negative. The sample consisted of 84 heavy drinking young men without a g-allele in the A118G (or A355G) single nucleotide polymorphism of the OPRM1 gene and 24 heavy drinking young men with at least one g-allele. Heavy drinking carriers of a g-allele showed relatively strong automatic approach tendencies for alcohol (approach bias). Unexpectedly, they also showed an approach bias for other appetitive stimuli. No approach bias was found for general positive or negative stimuli. These results suggest that automatic approach tendencies in response to appetitive stimuli could play a role in the etiology of addictive behaviors and related disorders. Further research is needed to investigate the specificity of this approach bias and possible gender differences.

The emotional Stroop effect in anxiety disorders: general emotional or disorder specificity?

Selective attentional biases, often documented with a modified Stroop task, are considered to play an important role in the etiology and maintenance of anxiety. Two competing explanations for these effects are selectivity for highly emotional words in general vs. selectivity for disorder-specific words. We tested these explanations in 32 patients with generalized anxiety disorder (GAD), 29 patients with social phobia (SP), and 31 non-anxious controls. Stimuli were of four kinds: GAD-related words, SP-related words, words with a neutral valence, and words with a positive valence. Different attentional biases were observed: GAD patients were slowed by all types of emotional words, while SP patients were distracted specifically by speech-related words.

Using temporal information to construct, update, and retrieve situation models of narratives.

Four experiments explored how readers use temporal information to construct and update situation models and retrieve them from memory. In Experiment 1, readers spontaneously constructed temporal and spatial situation models of single sentences. In Experiment 2, temporal inconsistencies caused problems in updating situation models similar to those observed previously for other dimensions of situation models. In Experiment 3, merely implied temporal order information was inferred from narratives, affecting comprehension of later sentences like explicitly stated order information. Moreover, inconsistent temporal order information prevented the creation and storage in memory of an integrated situation model. In Experiment 4, a temporal inconsistency increased processing time even if readers were unable to report the inconsistency. These results confirm the significance of the temporal dimension of situation models.

Selecting one among many referents in spatial situation models.

Five experiments related anaphor resolution to a classic memory variable, namely, interference created by multiple uses of a given object-concept, and by spatial distance of the referent from the reader's focus of attention. Participants memorized a diagram of a building with rooms containing objects, and then read narratives describing characters' activities there. Reading was self-paced word by word. Accessibility was measured by readers' time to understand anaphoric sentences containing a definite noun phrase referring to an object in its room. Spatial distance between the object and the current focus of attention increased reading times for names of the object, the room, and sentence wrap-up. Multiple examples of a target-object increased its reading time only if they were scattered across different rooms. An associative model of memory retrieval during text comprehension was used to interpret the complex pattern of results.

Temporal and spatial distance in situation models.

In two experiments, we investigated how readers use information about temporal and spatial distance to focus attention on the more important parts of the situation model that they create during narrative comprehension. Effects of spatial distance were measured by testing the accessibility in memory of objects and rooms located at differing distances from the protagonist's current location. Before the test probe, an intervening episode was inserted in the narrative. Story time distance was manipulated by stating that the intervening episode lasted for either minutes or hours. Discourse time--that is, time spent reading from prime to test--was manipulated by describing the intervening episode either briefly or at length. Clear effects of story time distance and spatial distance on accessibility were found, whereas discourse time distance did not affect accessibility. The results are interpreted as supporting constructionist theories of text comprehension.

[Strategic focusing of attention during narrative reading]. / Strategische Fokussierung der Aufmerksamkeit beim Lesen narrativer Texte.

In 2 experiments based on the constructionist view of text comprehension, we investigated whether readers are able to strategically use, in a problem solving matter, spatial and temporal information that varies in its relevance to the goals of the protagonists. In order to accomplish this, we varied the specificity of the protagonists' goal descriptions. Both experiments consisted of a reading section, a test, and a questionnaire, and differed only in respect to when the questionnaire was administered. The results of both experiments showed that readers were able to use spatial and temporal information of narrative texts in a strategic matter, and they even did so without explicit instruction. This focus of attention, however, was not uniformly reflected in the reading times. Memory data showed a clear disadvantage for temporal information as compared to spatial information. This was the case even though both types of information had been equally well identified in the questionnaire as crucial to the problem solving process of the protagonist.

A specific attentional bias in suicide attempters.

Selective attention in patients after an attempted suicide was investigated to find out whether a specific attentional bias for suicide-related materials exists and to clarify the possible role of emotions in the bias. Thirty-one patients who had previously attempted to commit suicide and 31 control participants took part in a modified Stroop task. The suicidal patients took significantly longer to name the colors of suicide-related words compared with other words, whereas color naming times of the control participants did not differ for suicide-related, neutral, positive, or negative words. Therefore, the attentional bias exhibited by suicidal patients was highly specific. There was no relation between the bias and measures of anxiety, depression, or hopelessness, whereas suicidal ideation correlated significantly with the attentional bias.

Don't worry and beware of white bears: thought suppression in anxiety patients.

The ability to suppress unwanted thoughts was investigated in patients with Generalized Anxiety Disorder (GAD; n = 29), Speech Phobics (n = 25), and nonanxious controls (n = 28). All participants spent 5 minutes thinking aloud about anything that came to mind while trying not to think of white bears. In another task, they thought aloud for 5 minutes while trying not to think of their main worry. Intrusions of unwanted thoughts were signaled by button presses and recorded on tape. In accordance with the disorder's definition and complaints of the GAD patients, they showed more intrusions of their main worry than of white bears. The opposite was true for other participants. Compared to a baseline measure, all participant groups were unable to reduce duration of main worry thoughts when trying to suppress them.

The metrics of spatial situation models.

The authors investigated the metrics of spatial distance represented in situation models of narratives. In 3 experiments, a spatial gradient of accessibility in situation models was observed: The accessibility of objects contained in the situation model decreased with increasing spatial distance between the object and the reader's focus of attention. The first 2 experiments demonstrated that this effect of spatial distance was purely categorical rather than Euclidean: Accessibility depended on the number of rooms located between the object and the focus of attention, not on the size of the rooms. Experiment 3 revealed, however, that participants were able to use information about Euclidean distance in a secondary task when necessary. The implications of these results for theories of narrative comprehension and hierarchical versus nonhierarchical theories of spatial memory are discussed.

Prevention of catheter-related infections by silver coated central venous catheters in oncological patients.

Catheter-related infection (CRI) is a serious complication of central venous catheterization. We have investigated the efficacy of a silver-coated polyurethane catheter (Pellethane, Fresenius AG, Germany) in preventing CRI in oncological patients receiving chemotherapy in a phase II study. From November 1992 through April 1994, 266 patients were assigned to receive single lumen catheters, either standard uncoated catheters (UC, n = 113) or silver-coated ones (SC, n = 120). Catheters were inserted into the internal jugular vein after institutional approval and informed consent. Duration of catheterization (UC vs. SC = 13.3 vs. 12.7 days) and leukopenia (< 1.0 x 10(9) WBC/l; 4.3 vs. 3.6 days) were similar in both groups demonstrating a comparable risk for infections. Skin reactions at the catheter entry site were recorded daily. CRI and colonization rates were studied by semiquantitatively culturing intradermal and intravascular segments. CRI were confirmed by blood cultures obtained via catheter and from peripheral veins in cases of suspected sepsis or at the end of catheterization. No adverse effects from the silver-coated catheter could be observed. The bacteriological results showed that SC were colonized (> 15 CFU) in 45.1% and UC in 44.2%. CRI developed in 21.2% of the UC patients but only in 10.2% of the SC patients (p = 0.011). We conclude that this new silver-coated central venous catheter is biocompatible and effective in reducing the incidence of catheter-related infections in oncological patients.

Biocompatibility of silver-coated polyurethane catheters and silver-coated Dacron material.

The local effects of silver-coated polyurethane catheters and Dacron material were compared to uncoated polyurethane catheters and Dacron material in a long-term implantation test using rabbits. The tissue-implant interaction was analysed by investigating the type and number of inflammatory cells, capillaries, fat tissue, the extent of fibrosis, thickness of the fibrous capsule, number and distribution of silver particles, and the size of giant cells. Silver-coated and uncoated materials displayed comparable signs of inflammation and tissue reaction.

In vitro evaluation of the antimicrobial efficacy and biocompatibility of a silver-coated central venous catheter.

Central venous catheter infection presents an important problem in modern medicine, leading sometimes to a life-threatening situation for the patient as well as contributing to prolonged hospital stay and to an increase in costs. We have evaluated the in vitro biocompatibility and antimicrobial activity of a silver-coated polyurethane catheter designed for use as a colonization-resistant, antiinfective catheter. Due to a comparatively low silver release, the catheter performed well in cell toxicity and blood compatibility tests as well as in acute toxicity tests done with mice. The antimicrobial activity was tested in stationary and dynamic bacterial adherence experiments using S. epidermidis, E. coli and P. aeruginosa as test strains. The silver-coated polyurethane catheter showed good ability to prevent microbial colonization of the catheter surface. Currently a clinical trial of the silver-coated catheter is under investigation.

Memory bias in panic disorder.

We investigated selective memory effects in patients with panic disorder. Thirty patients with panic disorder and 20 normal controls learned panic-related, strongly pleasant, and strongly unpleasant words. During the incidental learning task, Ss imagined scenes combining the referent of a presented word with themselves. After a distractor task, Ss took a free-recall test. Panic Ss showed enhanced memory for panic-related words but not for positive or negative words.

[Cognitive structuring by statistical graphics: effects on understanding and retention]. / Wissensstrukturierung durch statistische Graphen: Auswirkungen auf das Verstehen und Behalten.

We investigated how displaying the same set of data using different line graphs affects comprehension and retention of the data. In line graphs, the results of two-factor experiments can be displayed and structured in different ways by locating either one or the other independent variable on the abscissa. The experiment showed that the level of measurement as well as the number of levels of each independent variable affected comprehension and retention. Comprehension of graphs and retention of the information was better, if the graph showed an independent variable on the abscissa which was measured using an interval scale rather than a nominal scale, and when there were four rather than two levels. To account for the results, we propose a process model of graph comprehension.

Mood-congruent and mood-incongruent learning.

We report two experiments that investigate the effect of an induced mood on the incidental learning of emotionally toned words. Subjects were put in a happy or sad mood by means of a suggestion technique and rated the emotional valence of a list of words. Later on, they were asked to recall the words in a neutral mood. For words with a strong emotional valence, mood-congruent learning was observed: strongly unpleasant words were recalled better by sad subjects and strongly pleasant words were recalled better by happy subjects. The reverse was true for slightly toned words: here, mood-incongruent learning was observed. Both effects are predicted by a two-component processing model that specifies the effect of the mood on the cognitive processes during learning. Further evidence for the model is given by rating times measured in Experiment 2.