Decreased activation of the anterior cingulate in bipolar patients: an fMRI study (original) (raw)
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Neurocognitive Functioning in Bipolar Disorder
Clinical Psychology: Science and Practice, 2009
Neuropsychological processes may have direct bearing on the emotional dysregulation and functional impairments characteristic of bipolar disorder. Neuropsychological deficits that have been identified in adults and children with bipolar disorder include impairments in executive functions, declarative memory, attentional processes, and possibly working memory. Structural and functional magnetic resonance imaging and magnetic resonance spectroscopy studies of adults and children with bipolar disorder also indicate abnormalities in regions thought to underlie these neuropsychological deficits, including the basal ganglia, amygdala, and dorsolateral, orbitofrontal, and anterior cingulate cortices. Study of this area is made challenging by the heterogeneity of bipolar disorder, the heterogeneity of neuropsychological deficits among groups of patients with different clinical characteristics, the lack of specificity of neurocognitive deficits for bipolar disorder, and difficulty ascertaining whether deficits are inherent in the disorder, predate the disorder, or are influenced by mood state, course, treatment, and comorbidity with other disorders. In this review, we integrate the literature on neuropsychological functioning and neuroimaging in both children and adults with bipolar disorder, propose a nascent integrative model of cognitive function in bipolar disorder, and make suggestions for future studies and model development.
Brain functional changes across the different phases of bipolar disorder
The British journal of psychiatry : the journal of mental science, 2015
Little is known about how functional imaging changes in bipolar disorder relate to different phases of the illness. To compare cognitive task activation in participants with bipolar disorder examined in different phases of illness. Participants with bipolar disorder in mania (n = 38), depression (n = 38) and euthymia (n = 38), as well as healthy controls (n = 38), underwent functional magnetic resonance imaging during performance of the n-back working memory task. Activations and de-activations were compared between the bipolar subgroups and the controls, and among the bipolar subgroups. All participants were also entered into a linear mixed-effects model. Compared with the controls, the mania and depression subgroups, but not the euthymia subgroup, showed reduced activation in the dorsolateral prefrontal cortex, the parietal cortex and other areas. Compared with the euthymia subgroup, the mania and depression subgroups showed hypoactivation in the parietal cortex. All three bipolar...
Human Brain Mapping, 2010
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 underactivated 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.
Patients with bipolar disorder show differential executive dysfunctions: A case-control study
Psychiatry Research, 2016
Executive deficits in euthymic bipolar I disorder were examined in a fractionated manner based on the "Supervisory Attentional System" (SAS) model, and the relationship between the degree of executive impairment and the demographic and clinical characteristics of bipolar I participants was explored. A battery of neurocognitive tests capturing specific components of executive function was administered on 30 patients with bipolar I disorder in euthymic state, and compared with 30 healthy controls who were matched by age, gender and IQ. A differential impairment in executive function was demonstrated in euthymic bipolar I participants by using a fractionated approach of the SAS. Euthymic bipolar I patients were found to have significantly poorer performance in immediate and delayed visual memory; and in the executive domains of "initiation", "sustained attention", and "attention allocation and planning". Those with a greater number of executive impairments had lower IQ and higher negative sub-scores on PANSS. These findings might provide a the basis for further studies on identifying the executive components that are associated with particular disease characteristics of bipolar disorder, and those with poorer functional outcome, so that rehabilitation can be focused on the selective domains concerned.
BMC Psychiatry, 2013
Background: Cognitive deficits have been documented in patients with bipolar disorder. Further, it has been suggested that the degree and type of cognitive impairment differ between bipolar I and bipolar II disorder, but data is conflicting and remains inconclusive. This study aimed to clarify the suggested differences in cognitive impairment between patients with bipolar I and II disorder in a relatively large, clinically stable sample while controlling for potential confounders. Methods: 67 patients with bipolar I disorder, 43 with bipolar II disorder, and 86 randomly selected populationbased healthy controls were compared. A number of neuropsychological tests were administered, assessing verbal and visual memory and executive functions. Patients were in a stable phase during testing. Results: Patients with bipolar type I and type II were cognitively impaired compared to healthy controls, but there were no statistically significant differences between the two subtypes. The strongest predictor of cognitive impairment within the patient group was current antipsychotic treatment. Conclusions: The present study suggests that the type and degree of cognitive dysfunction is similar in bipolar I and II patients. Notably, treatment with antipsychotics -but not a history of psychosis -was associated with more severe cognitive impairment. Given that patients with bipolar I disorder are more likely to be on antipsychotic drugs, this might explain why some previous studies have found that patients with type I bipolar disorder are more cognitively impaired than those with type II.
European Psychiatry, 2008
Several lines of research suggest both dorsal and ventral prefrontal cortical dysfunction in bipolar disorder (BD). We used functional magnetic resonance imaging to compare patterns of brain activation in remitted BD patients and controls whilst performing tasks selected for their relative specificity in engaging either the dorsal (n-back sequential-letter working memory task) or ventral (gambling task) PFC. Seven BD patients were selected from participants of the Maudsley Bipolar Disorder Project on the basis of clinical remission, absence of cognitive deficits, and monotherapy with mood stabilisers. Subjects were individually matched by gender, age, and IQ to an equal number of healthy controls. In the n-back task, group differences were only present in response to increasing memory load. Patients did not show the predicted dynamic response in the dorsal PFC, but had increased activation in the parietal cortices. During the gambling task, controls showed significant activation in the ventral and dorsal PFC; this was attenuated in BD patients where increased activation was seen in lateral temporal and polar regions. Our findings suggest that there are trait abnormalities in dorsal and ventral PFC function in BD that may be more pronounced during tasks that rely on ventraledorsal PFC interaction.
Anterior cingulate subregion volumes and executive function in bipolar disorder
Bipolar Disorders, 2006
The anterior cingulate cortex (ACC) is of particular interest in bipolar disorder (BPD) because it is an important component of networks hypothesized to be involved in regulation of mood. The ACC is often examined morphometrically as a single structure; however, evidence from functional neuroimaging studies suggests that ACC subregions are behaviorally and functionally heterogeneous (1, 2). A review by Devinsky et al. (3) suggests that the rostral ACC may be involved in emotional processes, while the caudal ACC is involved with non-emotional cognitive processes. The caudal ACC has connections to the spinal cord and red nucleus and is thought to be involved in premotor functioning, response selection, and information processing (3). The rostral ACC, in contrast, has extensive connections to the amygdala, a structure in a network thought to be involved in the regulation of mood, as well as periaqueductal gray, Zimmerman ME, DelBello MP, Getz GE, Shear PK, Strakowski SM. Anterior cingulate subregion volumes and executive function in bipolar disorder.