Spontaneous and directed application of verbal learning strategies in bipolar disorder and obsessive-compulsive disorder

Neural correlates of the ADHD self-report scale

BACKGROUND

The ADHD Self Report Scale is a self-report measure that assesses attentional problems. We sought to validate the ASRS by establishing neural correlates using functional magnetic imaging in healthy controls and individuals with bipolar disorder (BD), who commonly exhibit attentional problems.

METHODS

ASRS questionnaires and functional MRI data in conjunction with the Multi-source Interference Task (MSIT) were collected from 36 healthy control and 36 BD participants. We investigated task specific changes in the dorsal anterior cingulate cortex (dACC, Brodmann area 32) and their correlations with ASRS subscale scores, inattention and hyperactivity, in both cohorts.

RESULTS

As hypothesized, the dACC showed significant increases in BOLD activation between the interference and noninterference conditions. For the ASRS scale as well as its Inattention and Hyperactivity subscales, there was a significant negative correlation with the dACC BOLD for the whole group.

CONCLUSIONS

The ASRS is sensitive to attentional difficulties in BD, suggesting that it is a valid tool for assessing attentional difficulties in patients with BD.

Obsessive-Compulsive Disorder

PURPOSE OF REVIEW

This article reviews current knowledge regarding diagnosis, pathophysiology, and treatment trends in obsessive-compulsive disorder (OCD), a severe, underrecognized, and chronic condition frequently encountered in neurologic practice.

RECENT FINDINGS

With a lifetime prevalence estimated at 2.5%, OCD is a common condition that can also present comorbidly with neurologic disease. The core symptoms of OCD are obsessions and compulsions. Obsessions are intrusive repetitive thoughts, urges, images, or impulses that trigger anxiety and that the individual is not able to suppress. Compulsions are repetitive behaviors or mental acts occurring in response to an obsession with the intention of reducing the distress caused by obsessions. Neuroimaging, neuropsychological, and pharmacologic studies suggest that the expression of OCD symptoms is associated with dysfunction in a cortico-striato-thalamo-cortical circuit. Evidence-based treatments for OCD comprise pharmacotherapy and cognitive-behavioral therapy. Selective serotonin reuptake inhibitors (SSRIs) are the first-line drugs recommended for OCD, but significant differences exist in their use for OCD compared to their use for other mood and anxiety conditions, including the need for higher dosage, longer trials necessitated by a longer lag for therapeutic response, and typically lower response rates. Cognitive-behavioral therapy, based on the principles of exposure and response prevention, shows results superior to pharmacologic treatments with lower relapse rates on long-term follow-up and thus should be considered in the treatment plan of every patient with OCD.

SUMMARY

OCD and obsessive-compulsive symptoms are frequently encountered in the neurologic clinic setting and require a high index of suspicion to effectively screen for them and an illness-specific therapeutic approach.

Memory performance predicts response to psychotherapy for depression in bipolar disorder: A pilot randomized controlled trial with exploratory functional magnetic resonance imaging

OBJECTIVE

This pilot randomized controlled trial compared Cognitive Behavior Therapy (CBT) and Supportive Psychotherapy (SP) for the treatment of depression in bipolar I disorder. We also examined whether exploratory verbal memory, executive functioning, and neural correlates of verbal memory during functional magnetic resonance imaging (fMRI) predicted change in depression severity.

METHODS

Thirty-two adults (ages 18-65) with DSM-IV bipolar I disorder meeting current criteria for a major depressive episode were randomized to 18 weeks of CBT or SP. Symptom severity was assessed before, at the mid-point, and after the 18-week intervention. All participants completed a brief pre-treatment neuropsychological testing battery (including the California Verbal Learning Test-2nd Edition, Delis Kaplan Executive Functioning System [DKEFS] Trail-making Test, and DKEFS Sorting Test), and a sub-set of 17 participants provided usable fMRI data while completing a verbal learning paradigm that consisted of encoding word lists.

RESULTS

CBT and SP yielded comparable improvement in depressive symptoms from pre- to post-treatment. Better retention of learned information (CVLT-II long delay free recall vs. Trial 5) and recognition (CVLT-II hits) were associated with greater improvement in depression in both treatments. Increased activation in the left dorsolateral prefrontal cortex and right hippocampus during encoding was also related to depressive symptom improvement.

LIMITATIONS

Sample size precluded tests of clinical factors that may interact with cognitive/neural function to predict treatment outcome.

CONCLUSION

Neuropsychological assessment and fMRI offer additive information regarding who is most likely to benefit from psychotherapy for bipolar depression.

Face and Object Perception in Body Dysmorphic Disorder versus Obsessive-Compulsive Disorder: The Mooney Faces Task

OBJECTIVES

Body dysmorphic disorder (BDD) is characterized by repetitive behaviors and/or mental acts occurring in response to preoccupations with perceived defects or flaws in physical appearance. There are some similarities, but also important differences, between BDD and obsessive-compulsive disorder (OCD), not just in terms of core clinical symptoms, but possibly in the domain of perception. This study compared the nature and extent of perceptual anomalies in BDD versus OCD and health controls (HC), using a modified Mooney task.

METHODS

We included 21 BDD, 19 OCD, and 21 HC participants, who were age-, sex-, and IQ-matched. A set of 40 Mooney faces and 40 Mooney objects arranged in three configurations (i.e., upright, inverted, or scrambled) were presented under brief (i.e., 500 ms) free-viewing conditions. Participants were asked to decide whether each image represented a human face, an object, or neither in a forced-choice paradigm.

RESULTS

The BDD group showed significantly reduced face and object inversion effects relative to the other two groups. This was accounted for by BDD participants being significantly more accurate in identifying inverted Mooney faces and objects than the other participants.

CONCLUSIONS

These data were interpreted as reflecting an overreliance on independent components at the expense of holistic (configural) processing in BDD. (JINS, 2017, 23, 471-480).

Cognitive Dysfunction in Obsessive-Compulsive Disorder

Obsessive-compulsive disorder (OCD) is a mental disorder featuring obsessions (intrusive thoughts) and compulsions (repetitive behaviors performed in the context of rigid rituals). There is strong evidence for a neurobiological basis of this disorder, involving limbic cortical regions and related basal ganglion areas. However, more research is needed to lift the veil on the precise nature of that involvement and the way it drives the clinical expression of OCD. Altered cognitive functions may underlie the symptoms and thus draw a link between the clinical expression of the disorder and its neurobiological etiology. Our extensive review demonstrates that OCD patients do present a broad range of neuropsychological dysfunctions across all cognitive domains (memory, attention, flexibility, inhibition, verbal fluency, planning, decision-making), but some methodological issues temper this observation. Thus, future research should have a more integrative approach to cognitive functioning, gathering contributions of both experimental psychology and more fundamental neurosciences.

Reduced prefrontal activation in pediatric patients with obsessive-compulsive disorder during verbal episodic memory encoding

OBJECTIVE

Patients with obsessive-compulsive disorder (OCD) often present with deficits in episodic memory, and there is evidence that these difficulties may be secondary to executive dysfunction, that is, impaired selection and/or application of memory-encoding strategies (mediation hypothesis). Semantic clustering is an effective strategy to enhance encoding of verbal episodic memory (VEM) when word lists are semantically related. Self-initiated mobilization of this strategy has been associated with increased activity in the prefrontal cortex, particularly the orbitofrontal cortex, a key region in the pathophysiology of OCD. We therefore studied children and adolescents with OCD during uncued semantic clustering strategy application in a VEM functional magnetic resonance imaging (fMRI)-encoding paradigm.

METHOD

A total of 25 pediatric patients with OCD (aged 8.1-17.5 years) and 25 healthy controls (HC, aged 8.1-16.9) matched for age, gender, handedness, and IQ were evaluated using a block design VEM paradigm that manipulated semantically related and unrelated words.

RESULTS

The semantic clustering strategy score (SCS) predicted VEM performance in HC (p < .001, R(2) = 0.635), but not in patients (p = .099). Children with OCD also presented hypoactivation in the dorsomedial prefrontal cortex (cluster-corrected p < .001). Within-group analysis revealed a negative correlation between Yale-Brown Obsessive Compulsive Scale scores and activation of orbitofrontal cortex in the group with OCD. Finally, a positive correlation between age and SCS was found in HC (p = .001, r = 0.635), but not in patients with OCD (p = .936, r = 0.017).

CONCLUSION

Children with OCD presented altered brain activation during the VEM paradigm and absence of expected correlation between SCS and age, and between SCS and total words recalled. These results suggest that different neural mechanisms underlie self-initiated semantic clustering in OCD.

Dissociative Experiences are Associated with Obsessive-Compulsive Symptoms in a Non-clinical Sample: A Latent Profile Analysis

INTRODUCTION

There has been a burgeoning literature considering the significant associations between obsessive-compulsive symptoms and dissociative experiences. In this study, the relationsips between dissociative symtomotology and dimensions of obsessive-compulsive symptoms were examined in homogeneous sub-groups obtained with latent class algorithm in an undergraduate Turkish sample.

METHOD

Latent profile analysis, a recently developed classification method based on latent class analysis, was applied to the Dissociative Experiences Scale (DES) item-response data from 2976 undergraduates. Differences in severity of obsessive-compulsive symptoms, anxiety and depression across groups were evaluated by running multinomial logistic regression analyses. Associations between latent class probabilities and psychological variables in terms of obsessive-compulsive sub-types, anxiety, and depression were assessed by computing Pearson's product-moment correlation coefficients.

RESULTS

The findings of the latent profile analysis supported further evidence for discontinuity model of dissociative experiences. The analysis empirically justified the distinction among three sub-groups based on the DES items. A marked proportion of the sample (42%) was assigned to the high dissociative class. In the further analyses, all sub-types of obsessive-compulsive symptoms significantly differed across latent classes. Regarding the relationships between obsessive-compulsive symptoms and dissociative symptomatology, low dissociation appeared to be a buffering factor dealing with obsessive-compulsive symptoms; whereas high dissociation appeared to be significantly associated with high levels of obsessive-compulsive symptoms.

CONCLUSION

It is concluded that the concept of dissociation can be best understood in a typological approach that dissociative symptomatology not only exacerbates obsessive-compulsive symptoms but also serves as an adaptive coping mechanism.

Obsessed not to forget: lack of retrieval-induced suppression effect in obsessive-compulsive disorder

The aim of the present study was to investigate the role of executive functions in resolving memory interference in a clinical sample of patients with obsessive-compulsive disorder (OCD). Retrieval of memories has been shown to involve some form of executive act that diminishes the accessibility of rival memory traces, leading to retrieval-induced forgetting (RIF). These executive control processes might suppress unwanted thoughts and irrelevant memories during competitive retrieval. We assessed RIF with the retrieval practice paradigm among 25 OCD patients and 25 healthy controls matched for age and education. Retrieval of target memories led to enhancement of target memory recall in both groups, but suppression of related memories (RIF) occurred only among controls. Our results suggest that suppression of irrelevant, interfering memories during competitive recall is impaired in OCD.

Executive functions and memory in autogenous and reactive subtype of obsessive-compulsive disorder patients

There are concurrently with different results of studies about cognitive functions of Obsessive-Compulsive Disorder (OCD), impairment in non-verbal memory and executive functioning in OCD, has shown consistent results in several studies. In this study, 62 OCD patients and 40 healthy controls were participated. Firstly, cognitive functions of OCD group and healthy control group were compared in terms of scores in Stroop Test, Wisconsin Cart Sorting Test (WCST), Auditory Consonant Trigram Test (ACTT), Controlled Word Association Test (CWAT), Rey Auditory Verbal Learning Test (RAVLT), Digit Span Test (DST). And then, two patient groups of OCD patients (patients with autogenous obsessions and patients with reactive obsessions) were compared in terms of the scores of same tests, with a hypothesis that claims, cognitive functions of patients with autogenous obsessions, who shown schizotypal personality features and thought disorder in higher ratio, will show more impairment than cognitive functions of patients with reactive obsessions. Significant impairment was found in OCD patients in terms of Stroop test and WCST scores when compared to scores of healthy controls. There was no difference pointed out between cognitive functions of patients with autogenous obsessions and reactive obsessions. Due to limited number of patients with autogenous obsessions in current study, any future research with greater sample size will be helpful to explain the cognitive functions in OCD with autogenous and reactive obsessions.

Involuntary social cue integration in patients with obsessive compulsive disorder

OBJECTIVE

Patients with obsessive compulsive disorder (OCD) have inferior social functioning compared to healthy controls, but the exact nature of these social deficits, and the underpinning mechanisms, are unknown. We sought to investigate social functioning in patients with OCD by measuring their involuntary/spontaneous processing of social cues using a specifically designed test, which might reveal deficits in these patients that explicit voluntary tasks do not detect.

METHODS

The sample of the study consisted of an OCD group (n = 25) and a control group (n = 26). Both groups performed an adaptation of the Social Distance Judgment Task (SDJT; Jellema et al., 2009), in which participants have to judge the geometrical distance between two human cartoon figures presented on a computer screen. Head/gaze direction and body direction were manipulated to be either compatible, i.e. both directed to the left or to the right (Compatible condition) or incompatible, i.e. body directed toward the observer (frontal view) and head/gaze directed to the left or right (Incompatible condition).

RESULTS

In the Compatible condition, controls nor OCD patients were influenced by the social cues in their judgments of the geometrical distances. However, in the Incompatible condition, where the attentional cue was more conspicuous, both groups were influenced by the cues, but the controls to a significantly larger extent than the OCD patients.

CONCLUSIONS

This study showed that patients with OCD are less likely, compared to controls, to automatically/spontaneously integrate the other's direction of attention into their visual percept. This may have resulted in their judgments of the geometrical distances between the agents to be more accurate than those of controls. The suggested impairment in automatically integrating social cues may have important repercussions for the social functioning of OCD patients.

Neuropsychological functioning in obsessive-compulsive disorder: are executive functions the key deficit?

OBJECTIVE

Although several studies have examined neuropsychological functions in obsessive-compulsive disorder (OCD), findings are not conclusive, predominantly due to small samples and assessment of limited domains. We aim to map the neuropsychological profile of OCD in a large sample with a comprehensive battery of tests.

METHOD

Neuropsychological functions were tested in 150 subjects with DSM-IV OCD and 205 healthy control subjects.

RESULTS

Subjects with OCD performed significantly worse than healthy control subjects on Colour Trails 1 time, Tower of Hanoi 3-disk time, Wisconsin Card Sorting Test categories completed, Iowa Gambling Task, Complex Figure Test immediate and delayed recall (p<0.001).

CONCLUSIONS

Subjects with OCD evince deficits in scanning, planning time, concept formation, decision making and encoding of non-verbal memory after controlling for the effects of age, gender and education. The profile is suggestive of a predominantly executive dysfunction, with difficulties in strategizing and organizing stimuli and cognitive resources for maximum efficiency. The findings implicate dorsolateral prefrontal, superior medial prefrontal and anterior cingulate cortices, suggesting that OCD might not be a purely orbitofronto-striatal disorder as previously conceptualized.

Neuropsychological correlates of insight in obsessive-compulsive disorder

OBJECTIVE

There are limited data on neuropsychological correlates of poor insight in obsessive-compulsive disorder (OCD). We hypothesize that poor insight may be associated with greater impairment in tasks of conflict resolution/response inhibition and possibly impairment in a task of verbal learning and memory.

METHOD

Insight and neuropsychological functions were assessed in 150 subjects with DSM-IV OCD. The neuropsychological data of 177 healthy control subjects were used for comparison.

RESULTS

Insight score correlated significantly with the Stroop Interference Test for conflict resolution/response inhibition (P = 0.002), and showed trends for significance with the Controlled Oral Word Association (COWA) average for verbal fluency (P = 0.021) and delayed recall on the Auditory Verbal Learning Test (AVLT) for verbal memory (P = 0.015). On regression analysis, the AVLT delayed recall, the COWA average, the Matrix score, the Yale-Brown Obsessive-Compulsive Scale total score, and current antipsychotic use emerged as significant predictors of poorer insight.

CONCLUSION

Poor insight is associated with greater impairments in conflict resolution/response inhibition, verbal memory, and fluency. Individuals with poorer insight may have difficulty in appropriately processing conflicting information, updating their memory with corrective information, and then accessing this corrective information to modify their irrational beliefs.

Semantic organizational strategy predicts verbal memory and remission rate of geriatric depression

OBJECTIVE

This study tests the hypothesis that the use of semantic organizational strategy during the free-recall phase of a verbal memory task predicts remission of geriatric depression.

METHODS

Sixty-five older patients with major depression participated in a 12-week escitalopram treatment trial. Neuropsychological performance was assessed at baseline after a 2-week drug washout period. The Hopkins Verbal Learning Test-Revised was used to assess verbal learning and memory. Remission was defined as a Hamilton Depression Rating Scale score of ≤ 7 for 2 consecutive weeks and no longer meeting the DSM-IV-TR criteria for major depression. The association between the number of clusters used at the final learning trial (trial 3) and remission was examined using Cox's proportional hazards survival analysis. The relationship between the number of clusters utilized in the final learning trial and the number of words recalled after a 25-min delay was examined in a regression with age and education as covariates.

RESULTS

Higher number of clusters utilized predicted remission rates (hazard ratio, 1.26 (95% confidence interval, 1.04-1.54); χ(2)  = 4.23, df = 3, p = 0.04). There was a positive relationship between the total number of clusters used by the end of the third learning trial and the total number of words recalled at the delayed recall trial (F(3,58) = 7.93; p < 0.001).

CONCLUSIONS

Effective semantic strategy use at baseline on a verbal list learning task by older depressed patients was associated with higher rates of remission with antidepressant treatment. This result provides support for previous findings indicating that measures of executive functioning at baseline are useful in predicting antidepressant response.

Alpha amplitude and phase locking in obsessive-compulsive disorder during working memory

Alpha event-related desynchronization (ERD) and synchronization are known to reflect brain activation and inhibition, respectively. Alpha phase locking seems to reflect the timing in the cortical process. In a previous study, lower alpha ERD was related to working memory in obsessive-compulsive disorder (OCD) patients than in controls during the retention and retrival phases, but not in the encoding phase. However, memory deficits in OCD patients are known to be related to executive failure during the encoding phase. Thus, focusing on the encoding phase, we tested the level of alpha amplitude and phase locking in OCD patients according to memory load. The EEGs of fifteen OCD patients and fifteen controls were recorded during a Sternberg working memory task. The behavioral performance of the OCD patients was normal. However, the OCD group yielded significantly lower ERD and stronger phase locking. As memory load rose, ERD and phase locking significantly increased in both groups. A difference in event-related alpha oscillation was observed in the encoding phase. Lower alpha modulation in the OCD patient simplied abnormality of the excitatory/inhibitory process in the brain, and increased phase locking might reflect excessive attentional excitability.

Fronto-temporal dysregulation in asymptomatic bipolar I patients: a paired associate functional MRI study

Bipolar disorder is associated with persistent declarative memory disturbances, but the neural basis of these deficits is not well understood. We used fMRI to investigate brain activity during performance on a face-name paired associate task, which allows for the dissociation of encoding and recall-related memory processes. Fifteen clinically remitted bipolar I disorder patients and 24 demographically matched healthy comparison subjects were scanned during task performance. At the voxel level, bipolar patients showed reduced cortical activation, relative to controls, in multiple task-related brain regions during encoding. During recognition, bipolar patients under-activated left hippocampal and parahippocampal regions, despite adequate task performance. Region of interest analyses indicated that, during encoding, bipolar patients had greater bilateral dorsolateral prefrontal (DLPFC) activity than healthy subjects. In contrast, during recognition patients showed hypo-activation relative to controls in the right, but not the left, DLPFC. Although hippocampal activity did not differ between groups during encoding, bipolar patients failed to activate hippocampal regions to the same extent as healthy subjects during recognition. Finally, while better task performance was associated with recognition-related hippocampal activity in healthy subjects, bipolar patients showed an inverse relationship between task performance and hippocampal activity. Remitted bipolar patients over-engaged dorsolateral prefrontal regions when learning face-name pairs, but relative hypoactivation in both prefrontal and medial temporal regions during recognition. These findings suggest a neural basis for the long-term memory deficits consistently observed in patients with bipolar disorder; further, as these patterns appear in symptomatically remitted patients, they are unlikely to be an artifact of mood symptoms.

Impaired visuospatial associative memory and attention in obsessive compulsive disorder but no evidence for differential dopaminergic modulation

RATIONALE

Patients with obsessive compulsive disorder (OCD) demonstrate impaired cognition in some selected domains. Although serotoninergic dysfunction has been implicated in OCD, recent evidence suggests that dopamine may play a role as well.

OBJECTIVE

The aim of the study was to evaluate learning and working memory in OCD and to determine the effects of dopaminergic manipulations on these capacities.

METHODS

Visuospatial associative memory and spatial and verbal working memory were examined in 18 nondepressed patients with OCD and 18 matched healthy controls. The study further investigated whether acute administration of dopamine D2/D3 receptor agonist and antagonist would differentially modulate cognition in OCD. Each participant underwent the cognitive battery three times in a randomized double-blind, placebo-controlled crossover design.

RESULTS

Significant impairments in patients compared with controls were noted on the Cambridge Neuropsychological Test Automated Battery (CANTAB) paired associates learning (PAL) and a measure of sustained attention (rapid visual information processing, RVIP) that persisted across all sessions, with deficient strategy in the CANTAB spatial working memory task in the first session alone. Although the dopamine D2/D3 agonist, pramipexole, led to poorer performance on the PAL and RVIP tasks, no differential effects were noted between the two groups. No significant effects were noted for the D2/D3 antagonist, amisulpride.

CONCLUSIONS

The results are consistent with a specific associative memory deficit in OCD that remained robust despite possible practice effects and compensatory strategies and point to abnormal medial temporal lobe involvement in OCD in addition to the previously implicated frontostriatal loops, with no clear evidence of D2 receptor mediation.

Individual Differences in Episodic Memory: The Role of Self-initiated Encoding Strategies

Individuals' abilities to form and retrieve episodic memories vary widely. Consistent with this, there are substantial individual differences in brain activity during encoding and retrieval that are associated with individual differences in memory performance. Growing evidence suggests that individual differences in self-initiated encoding strategy use play an important role in individual differences in episodic memory and brain activity during intentional encoding. This review examines the role of individual differences in self-initiated encoding strategy use in individual differences in episodic memory, and outlines the major findings of brain lesion and functional neuroimaging studies that characterize the neural correlates of individual differences in self-initiated encoding strategy use. The relevance of individual differences in self-initiated encoding strategy use to understanding episodic memory impairments and alterations in brain activity in clinical populations such as individuals with schizophrenia is also discussed.

Memory for an imagined pathway and strategy effects in sighted and in totally congenitally blind individuals

The literature reports mixed results on the imagery abilities of the blind, at times showing a difference between sighted and blind individuals and at other times similarities. However, the possibility that the results are due to different strategies spontaneously used in performing the imagery tasks has never been systematically studied. A large group of 30 totally congenitally blind (TCB) individuals and a group of 30 sighted individuals matched for gender age and schooling were presented with a mental pathway task on a complex two-dimensional (5 x 5) matrix. After administering the task, participants were interviewed in order to establish the strategy they used. Results showed that both sighted and TCB may use a spatial mental imagery, a verbal or a mixed strategy in carrying out the task. Differences between the groups emerged only when last location and then entire pathway had to be remembered rather than just the last position, and were clearly affected by the type of strategy. Specifically, TCB performed more poorly than the sighted individuals when they used a spatial mental imagery strategy, whereas the two groups had a similar performance with a verbal strategy.

An fMRI investigation of working memory and sadness in females with bipolar disorder: a brief report

OBJECTIVE

Functional magnetic resonance imaging (fMRI) studies have documented abnormalities in the dorsolateral prefrontal cortex (DLPFC) and anterior cingulate cortex in bipolar disorder in the context of working memory tasks. It is increasingly recognized that DLPFC regions play a role in mood regulation and the integration of emotion and cognition. The purpose of the present study was to investigate with fMRI the interaction between acute sadness and working memory functioning in individuals with bipolar disorder.

METHODS

Nine depressed individuals with DSM-IV bipolar I disorder (BP-I) and 17 healthy control participants matched for age, gender, education, and IQ completed a 2-back working memory paradigm under no mood induction, neutral state, or acute sadness conditions while undergoing fMRI scanning. Functional MRI data were analyzed with SPM2 using a random-effects model.

RESULTS

Behaviorally, BP-I subjects performed equally well as control participants on the 2-back working memory paradigm. Compared to control participants, individuals with BP-I were characterized by more sadness-specific activation increases in the left DLPFC (BA 9/46) and left dorsal anterior cingulate (dACC).

CONCLUSIONS

Our study documents sadness-specific abnormalities in the left DLPFC and dACC in bipolar disorder that suggest difficulties in the integration of emotion (sadness) and cognition. These preliminary findings require further corroboration with larger sample sizes of medication-free subjects.

Language impairment in euthymic, elderly patients with bipolar disorder but no dementia

BACKGROUND

Neurocognitive impairment is known to occur in euthymic bipolar patients, but language alterations have not been thoroughly investigated. The aim of this study is to examine the performance in language tests of a sample of elderly patients with bipolar disorder.

METHODS

We studied 33 euthymic elderly patients with bipolar disorder but no dementia and 33 healthy individuals, matched for age and education, who were compared in terms of their CAMCOG global score and its subitems.

RESULTS

The scores obtained in language-related abilities for patients and controls, respectively, were: language (total): 27.3 (1) and 28.5 (1), p < 0.0001; comprehension: 8.6 (0.5) and 8.9 (0.3), p = 0.006; production: 18.7 (1) and 19.6 (0.9), p = <0.0001; abstraction: 6.8 (1.1) and 7.3 (0.7), p = 0.016; verbal fluency: 16.3 (4.3) and 19.6 (4.1), p = 0.003.

CONCLUSION

A mild but significant impairment in language-related ability scores was detected when comparing patients and controls.

Memory and executive functioning in obsessive-compulsive disorder: a selective review

BACKGROUND

The neurocognitive deficits that underlie the unique features of obsessive-compulsive disorder (OCD) are not yet completely understood. This paper reviews the main neuropsychological findings in memory and executive functioning in this disorder, and examines a number of challenges facing this area of research.

METHOD

A selective review of the neuropsychological literature on OCD was conducted using MEDLINE and drawing on literature known to the authors.

RESULTS

The neuropsychological profile of OCD appears to be one of primary executive dysfunction. Although memory functioning may be affected, these deficits appear secondary to an executive failure of organizational strategies during encoding. On tasks of executive functioning patients with OCD demonstrate increased response latencies, perseveration of responses, and difficulties utilizing feedback to adapt to change.

LIMITATIONS

A statistical meta-analysis was not performed and only the cognitive domains of memory and executive functioning were examined.

CONCLUSIONS

Given the prominence of chronic doubt and indecision in clinical settings, it is surprising that decision making as a cognitive construct as related to OCD has not received greater attention in the neuropsychological literature. On the basis of emerging literature we suggest that it is a potential area of dysfunction and one that warrants further investigation as it may assist in enhancing our understanding of the pathophysiology of OCD.

Gender differences in brain activity evoked by muscle and cutaneous pain: a retrospective study of single-trial fMRI data

Gender greatly influences pain processing. Not only do females display greater pain sensitivity, many chronic pain conditions affect females more than males. Although gender-based differences in pain sensitivity may be related to cultural and social factors, animal studies also reveal gender differences in pain sensitivity, suggesting that physiological factors may contribute to differences in the processing of pain in males and females. It has been recently reported that noxious cutaneous heat stimuli evoke gender-based differences in activity in some brain regions. Given that most chronic pain conditions, including those with gender bias are of "deep" origin (e.g. arising in muscle, joints or viscera), we investigated whether gender differences also exist in the central processing of muscle pain. In 24 healthy adults we used functional magnetic resonance imaging (fMRI) to measure signal intensity changes during muscle and cutaneous pain induced by intramuscular and subcutaneous injections of hypertonic saline, respectively. In addition to activating the "pain neuromatrix", i.e. cingulate, insular, somatosensory and cerebellar cortices, both muscle pain and cutaneous pain evoked gender-based differences in the mid-cingulate cortex, dorsolateral prefrontal cortex, hippocampus and cerebellar cortex. These differences may reflect differences in emotional processing of noxious information in men and women and may underlie the gender bias that exists in many chronic pain conditions.

Cognitive retraining for organizational impairment in obsessive-compulsive disorder

Individuals with obsessive-compulsive disorder (OCD) have difficulties in organizing information during encoding associated with subsequent memory impairments. This study was designed to investigate whether impairments in organization in individuals with OCD can be alleviated with cognitive training. Thirty-five OCD subjects and 36 controls copied and recalled the Rey-Osterrieth Complex Figure Test (RCFT) [Osterrieth, P.A., 1944. Le test de copie d'une figure complexe: Contribution a l'étude de la perception et de la memoire (The test of copying a complex figure: A contribution to the study of perception and memory). Archive de Psychologie 30, 286-350.] before being randomly assigned to a training or non-training condition. The training condition was designed to improve the ability to organize complex visuospatial information in a meaningful way. The intervention phase was followed by another copy and recall trial of the RCFT. Both OCD and control subjects who underwent training improved more in organization and memory than subjects who did not receive organizational training, providing evidence that the training procedure was effective. OCD subjects improved more in organizational during encoding than control subjects, irrespective of whether or not they had received training. This suggests that organization impairment in OCD affects primarily the ability to spontaneously utilize strategies when faced with complex, ambiguous information but that the ability to implement such strategies when provided with additional trials is preserved. These findings support a distinction in OCD between failure to utilize a strategy and incapacity to implement a strategy.

Strategic memory in adults with anorexia nervosa: are there similarities to obsessive compulsive spectrum disorders?

OBJECTIVE

There is growing interest in the relationship between anorexia nervosa (AN) and obsessive-compulsive (OC) spectrum disorders (e.g., OCD, body dysmorphic disorder [BDD]). Previous neuropsychological investigations of OC spectrum disorders have identified problems with the efficient use of strategy on complex measures of learning and memory. This study evaluated nonverbal strategic memory in AN outpatients using an approach previously applied to OC spectrum disorders.

METHOD

Eighteen patients with AN and 19 healthy control participants completed the Rey-Osterrieth Complex Figure Test (RCFT), a widely used measure of nonverbal strategic planning, learning, and memory.

RESULTS

Individuals with AN differed significantly from healthy controls in the organizational strategies used to copy the RCFT figure, and they recalled significantly less information on both immediate and delayed testing. Multiple regression analyses indicated that group differences in learning were mediated by copy organizational strategies.

CONCLUSION

These results are identical to study findings in OCD and BDD, indicating important shared neuropsychological features among AN and these OC spectrum disorders. As in OCD and BDD, the essential cognitive deficit in AN was impaired use of organizational strategies, which may inform our understanding of the pathophysiology of AN and potentially offer treatment implications.

Cognitive impairment in bipolar II disorder

BACKGROUND

Persistent impairments in neurocognitive function have been described in bipolar disorder.

AIMS

To compare the cognitive performance of patients with bipolar II disorder with that of patients with bipolar I disorder and a healthy control group.

METHOD

The study included 71 euthymic patients with bipolar disorder (38 bipolar I, 33 bipolar II), who were compared on clinical and neuropsychological variables (e.g. executive function, attention, verbal and visual memory) and contrasted with 35 healthy controls on cognitive performance.

RESULTS

Compared with controls, both bipolar groups showed significant deficits in most cognitive tasks including working memory (DigitSpan Backwards, P=0.002) and attention (DigitSpan Forwards, P=0.005; Trail Making Test, P=0.001). Those with type II disorders had an intermediate level of performance between the bipolar I group and the control group in verbal memory (P<0.005) and executive functions (Stroop interference task, P=0.020).

CONCLUSIONS

Cognitive impairment exists in both subtypes of bipolar disorder, although more so in the bipolar I group. The best predictors of poor psychosocial functioning in bipolar II disorder were subclinical depressive symptoms, early onset of illness and poor performance on a measure related to executive function.

Alterações neuropsicológicas no transtorno bipolar

OBJETIVO: Revisão sistemática dos estudos controlados publicados nos últimos 15 anos sobre alterações neuropsicológicas no transtorno bipolar. MÉTODO: Foi realizado um levantamento bibliográfico no Medline, Lilacs, PubMed e ISI, selecionando-se o período de 1990 a 2005. Os estudos foram organizados a partir da comparação entre a amostra selecionada (bipolar versus outra patologia versus controles saudáveis). Nós só incluímos estudos controlados e com uma amostra de pacientes maior que 10, totalizando 73 artigos, do quais 53 foram selecionados para esta revisão. RESULTADOS: Pacientes com transtorno bipolar apresentam dificuldades em vários domínios cognitivos, sendo que alguns persistem mesmo após remissão dos sintomas. Os déficits encontrados se localizaram basicamente nas funções executivas. Na comparação com pacientes portadores de esquizofrenia, os bipolares apresentam perfil de alterações cognitivas mais leves, o que aponta para diferenças em termos de prognóstico da doença e para anormalidades em circuitos neuroanatômicos específicos. Houve correlação positiva entre déficits cognitivos e número de episódios ou internações. As medicações utilizadas para estabilização do humor podem ter um impacto negativo na cognição. CONCLUSÕES: Os prejuízos são sugestivos de disfunção em circuitos fronto-estriatais específicos que podem, em parte, explicar as dificuldades na adaptação psicossocial destes pacientes. Estudos futuros devem avaliar a eficácia de programas de reabilitação neuropsicológica, os quais visam, por meio de treinos cognitivos, minimizar o impacto dos déficits encontrados na vida diária dos pacientes.

Equivalent Current Dipole of Word Repetition Effects in Patients with Obsessive-Compulsive Disorder

We investigated cortical source localization of word repetition effects in patients with obsessive-compulsive disorder (OCD) by employing the equivalent current dipole (ECD) model with high-density 128 channels EEG and individual MRI as a realistic head model. Twelve OCD patients and 13 healthy control subjects performed a word/nonword discrimination task, in which the words and nonwords were visually presented, and some of the words appeared twice with a lag of one or five items. During the 200-500 ms post-stimulus period, the control group showed more positivity in the ERPs elicited by old words than in those elicited by new words, whereas the OCD patients did not. Furthermore, the OCD patients showed prolonged response times to the old words, as compared to the controls. We calculated the location and the power of the ECD sources at approximately 400 ms post-stimulus with the peak mean global field potentials. In both groups, the sources of word repetition effects were determined to be located in the inferior frontal gyrus. The right ECD powers of the ERP generators elicited by the new words were significantly higher in the OCD patients than in the control subjects. The OCD patients also exhibited significant alterations in the hemispheric asymmetry of ECD power during the processing of new words. These results suggest that OCD patients suffer from the encoding deficits in word processing, particularly in the left hemisphere.