Perseveration induces dissociative uncertainty in obsessive-compulsive disorder

Memory confidence and memory accuracy deterioration following repeated checking: A systematic review and meta-analysis

BACKGROUND AND OBJECTIVES

Rachman (2002) proposed a reciprocal detrimental relationship between repeated checking and memory confidence. Many experimental studies have indicated that repeated checking causes memory confidence deterioration while having no or little impact on memory accuracy. Thus, our main objective was to carry out a comprehensive meta-analysis to synthesize the existing research. Investigating the potential heterogeneity across studies using several moderator variables was also of interest.

METHODS

The comprehensive search of several databases yielded 29 studies comprising 67 substudies (N = 2180). Considering the substantial heterogeneity across these (sub)studies, data were analyzed using a random-effects meta-analytic approach. Subgroup analyses and meta-regressions were also carried out to explain some of the heterogeneity across studies.

RESULTS

The pooled effect size (Hedges' g) was equal to 0.870 (95% CI = 0.712-1.027, p < 0.001) for memory confidence and 0.213 (95% CI = 0.118-0.307, p < 0.001) for memory accuracy. However, we found evidence of publication bias in the literature. For both outcome variables, the effect was larger in studies inducing high responsibility or using real stimuli. A greater number of repeated checks was only associated with memory confidence decline.

LIMITATIONS

Results obtained from the analogue samples may have lower generalizability to people with OCD.

CONCLUSIONS

Repeated checking considerably deteriorates memory confidence while having a minor effect on memory accuracy. It is not clear whether memory accuracy contributes to memory confidence deterioration, particularly because memory accuracy declines were moderate in studies inducing high responsibility or using real objects.

Obsessive-compulsive symptoms and dissociative experiences: Suggested underlying mechanisms and implications for science and practice

A strong and specific link between obsessive-compulsive disorder or symptoms (OCD/S) and a tendency for dissociative experiences (e.g., depersonalization-derealization, absorption and imaginative involvement) cannot be explained by trauma and is poorly understood. The present theoretical formulation proposes five different models conceptualizing the relationship. According to Model 1, dissociative experiences result from OCD/S through inward-focused attention and repetition. According to Model 2, dissociative absorption causally brings about both OCD/S and associated cognitive risk factors, such as thought-action fusion, partly through impoverished sense of agency. The remaining models highlight common underlying causal mechanisms: temporo-parietal abnormalities impairing embodiment and sensory integration (Model 3); sleep alterations causing sleepiness and dreamlike thought or mixed sleep-wake states (Model 4); and a hyperactive, intrusive imagery system with a tendency for pictorial thinking (Model 5). The latter model relates to Maladaptive Daydreaming, a suggested dissociative syndrome with strong ties to the obsessive-compulsive spectrum. These five models point to potential directions for future research, as these theoretical accounts may aid the two fields in interacting with each other, to the benefit of both. Finally, several dissociation-informed paths for further developing clinical intervention in OCD are identified.

Deep brain stimulation of the subthalamic nucleus to improve symptoms and cognitive functions in patients with refractory obsessive-compulsive disorder: a longitudinal study

There are conflicting results regarding the effect of deep brain stimulation (DBS) of different regions on the cognitive functions of patients with severe refractory obsessive-compulsive disorder (OCD). Moreover, it is not yet clear whether the rate of improvement in obsession-compulsion symptoms and cognitive functions following DBS is interrelated. We investigated the effect of the subthalamic nucleus (STN)-DBS on both the severity of symptoms and cognitive functions of patients and also investigated the possible interrelationship between the two. Twelve patients (10 males and two females; 56.17 ± 4.52 years old) were assessed before and 1 month and 3 months after the DBS surgery using the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS), the N-Back, the selective and divided attention (SDA), the Tower of London (TOL), and the Wisconsin Card Sorting (WCS) tests. We found that the severity of symptoms and cognitive functions improved significantly after DBS and this effect lasted at least up to 3 months. Furthermore, it was revealed that the severity of symptoms and cognitive profiles of patients were significantly correlated. Compulsion severity had the highest correlation with perseveration errors, while obsession severity was most correlated with the number of n-back errors. Based on our findings, it seems that the STN acts at least to some extent as a common functional/anatomical ground for the severity of symptoms and cognitive functions of patients with severe refractory OCD, and it can probably be considered as the region of interest for DBS in this group of patients.

Dopaminergic drug treatment remediates exaggerated cingulate prediction error responses in obsessive-compulsive disorder

RATIONALE

Patients with obsessive-compulsive disorder (OCD) have been found to show exaggerated error responses and prediction error learning signals in a variety of EEG and fMRI tasks, with data converging on the anterior cingulate cortex as a key locus of dysfunction. Considerable evidence has linked prediction error processing to dopaminergic function.

OBJECTIVE

In this study, we investigate potential dopaminergic dysfunction during reward processing in the context of OCD.

METHODS

We studied OCD patients (n = 18) and controls (n = 18) whilst they learned probabilistic associations between abstract stimuli and monetary rewards in the fMRI scanner involving administration (on separate visits) of a dopamine receptor agonist, pramipexole 0.5 mg; a dopamine receptor antagonist, amisulpride 400 mg; and placebo. We fitted a Q-learning computational model to fMRI prediction error responses; group differences were examined in anterior cingulate and nucleus accumbens regions of interest.

RESULTS

There were no significant group, drug, or interaction effects in the number of correct choices; computational modeling suggested a marginally significant difference in learning rates between groups (p = 0.089, partial ƞ² = 0.1). In the imaging results, there was a significant interaction of group by drug (p = 0.013, partial ƞ² = 0.13). OCD patients showed abnormally strong cingulate signaling of prediction errors during omission of an expected reward, with unexpected reduction by both pramipexole and amisulpride (p = 0.014, partial ƞ² = 0.26, 1-β error probability = 0.94). Exaggerated cingulate prediction error signaling to omitted reward in placebo was related to trait subjective difficulty in self-regulating behavior in OCD.

CONCLUSIONS

Our data support cingulate dysfunction during reward processing in OCD, and bidirectional remediation by dopaminergic modulation, suggesting that exaggerated cingulate error signals in OCD may be of dopaminergic origin. The results help to illuminate the mechanisms through which dopamine receptor antagonists achieve therapeutic benefit in OCD. Further research is needed to disentangle the different functions of dopamine receptor agonists and antagonists during bidirectional modulation of cingulate activation.

Trapped in a Daydream: Daily Elevations in Maladaptive Daydreaming Are Associated With Daily Psychopathological Symptoms

Background: Maladaptive Daydreaming (MD) characterizes individuals who engage in vivid, fanciful daydreaming for hours on end, neglecting real-life relationships and responsibilities, resulting in clinical distress and functional impairment. Sufferers have embraced the term MD in cyber-communities devoted to this problem because it seemed to uniquely fit their experience and since existing diagnostic labels and their therapies seemed inadequate. However, scientific research in the field has been scarce, relying on cross-sectional or case study designs. Existing knowledge on MD suggests the involvement of dissociative and obsessive-compulsive symptoms, as well as positive reinforcement comparable to processes in addiction disorders. The present study aimed to rigorously explore factors that accompany MD employing a longitudinal daily-diary design, hypothesizing that temporal increases in MD will associate concurrently with, and will temporally precede, other symptoms and emotional changes. In addition, we aimed to explore which symptoms may act as precursors to increases in MD, in order to identify possible mechanisms bringing about daydreaming in these individuals. Methods: In a sample of 77 self-diagnosed individuals with MD we assessed relevant daily symptoms for 14 days, including MD, depression, general anxiety, social anxiety, obsessive-compulsive symptoms, and dissociation, as well as positive and negative emotion. Results: Increases in MD were strongly related to concurrent increases in all other symptoms and negative emotion, and to decreased positive emotion. Obsessive-compulsive symptoms, dissociation, and negative emotion also temporally followed MD. Obsessive-compulsive symptoms were the only consistent temporal antecedent of MD. Conclusions: MD and obsessive-compulsive symptoms coincided in what seems to be a vicious cycle; understanding possible shared mechanisms between these symptoms may inform our understanding of the etiology of MD. For example, Serotonin levels may possibly be involved in the development or maintenance of this condition. The findings may also provide clues as to potentially beneficial interventions for treating MD. For example, perhaps utilizing response prevention techniques may be useful for curbing or intercepting unwanted daydreaming. Future studies on MD should address its compulsory nature.

Intolerance of Uncertainty in eating disorders: An update on the field

Pathological fear and anxiety regarding food, eating, weight and body shape are at the core of eating disorder (ED) psychopathology. To manage anxiety, patients develop complicated repertoires of ritualistic and repetitive behaviours, which can lead to total functional impairment. Yet the cognitive processes underlying anxiety, fear, and anxiety-driven behaviours in EDs remain poorly understood. Intolerance of Uncertainty (IU) is defined as a tendency to react negatively on an emotional, cognitive, and behavioural level to uncertain situations and events. There is substantial evidence that IU is a transdiagnostic process that contributes to the maintenance of anxiety disorders; however, IU may also be relevant to the understanding and treatment of EDs. The current review summarises the growing literature examining IU in relation to ED symptoms, including restriction, bingeing, purging, ritualised behaviours, reassurance-seeking and body checking. Extending from the obsessive-compulsive disorder (OCD) and anxiety disorder literature, we propose that IU provides a novel theoretical and clinical framework from which to understand the anxiety, fixation with rules and rituals, and the cognitively rigid profile that is characteristic of ED presentations. We conclude with suggestions for future research, and discuss IU as a potential treatment target for core features of EDs and comorbid symptoms.