The role of encoding strategies in contextual memory deficits in patients with bipolar disorder

Unraveling the role of retrieval deficits in autobiographical memory impairment in schizophrenia: A comparison of involuntary and voluntary autobiographical memories

Patients with schizophrenia show severe autobiographical memory impairment, thought to reflect retrieval deficits caused by executive dysfunction. However, prior research has focused exclusively on strategic (voluntary) retrieval, and ignored involuntary retrieval resulting from automatic and associative processes, involving minimal cognitive control. We report two studies with patients diagnosed with schizophrenia (Ns = 40 and 50 respectively) comparing their impairment in involuntary versus voluntary autobiographical memory. We use two different methodologies, not previously used in schizophrenia research: a naturalistic study involving real-life data and an experimental setup. Both studies consistently showed that involuntary and voluntary autobiographical memories were similarly impaired in schizophrenia. The absence of interaction effects between group and retrieval suggests that schizophrenic patients did not benefit from memory tasks involving little retrieval effort. These findings suggest that autobiographical memory impairment in schizophrenia are not caused by problems with self-initiated voluntary retrieval, but instead likely reflect encoding or binding deficits.

Episodic memory boosting in older adults: exploring the association of encoding strategies and physical activity

Background: Contextual memory is susceptible to the effects of aging and its impairment compromises episodic memories and quality of life in older adults. Objective: Compare the effects of cognitive support on incidental contextual memory free recall and recognition with a naturalistic experimental paradigm and explore the association of encoding strategies and physical activity on memory improvement. Methods: Subjects (≥60 years, n = 52) were assigned to one of two encoding conditions for the contextual memory task: with or without an incidental associative instruction to encourage association of an item to its spatial context. Immediate free recall and recognition tests were run to assess the encoding instruction efficiency. The association of memory performance and physical activity was analyzed using the scores on the International Physical Activity Questionnaire (IPAQ) to subdivide each experimental group into Low IPAQ (below median) and High IPAQ (above median) subgroups. Results: The associative encoding instruction increased contextual memory free recall and recognition, with greater effects on free recall. The most robust associations between physical activity and contextual memory were also seen on free recall, in which higher levels of physical activity corresponded to increased baseline performance (non-associative encoding condition) and greater improvement of memory by the encoding support (associative encoding condition). Conclusion: Cognitive support at encoding can improve contextual memory free recall and recognition, suggesting they are prone to rehabilitation. Moreover, higher physical activity levels were positively associated with encoding strategies on contextual memory improvement, increasing the availability of latent process-based components of the cognitive reserve.

Mental health in familial caregivers of Alzheimer's disease patients: are the effects of chronic stress on cognition inevitable?

Familial caregivers of Alzheimer's disease (AD) patients experience an emotional and physical burden which characterizes a chronic stress condition. The resulting hypothalamic-pituitary-adrenal axis dysfunction favors an imbalance of neurotoxic/neuroprotective factors and causes cognitive impairments, increasing the caregivers' risk for cognitive decline and compromising their ability to provide adequate care of the patient. Therefore, the present study aimed to investigate the reversibility of the cognitive impairments of familial caregivers of AD patients during their caregiving-related chronic stress condition. Thirty-three caregivers (61.42 + 2.68 years; 27 women) and thirty-four controls (57.91 ± 2.16 years, 20 women) were evaluated for their cognitive functioning (attention, executive function, processing speed and memory) with a neuropsychological battery (Digit-span, Trail Making, Stroop and the Logical Memory tests). Subjects' cortisol/dehydroepiandrosterone (DHEA) ratios were determined by radioimmunoassay, and their brain-derived neurotrophic factor (BDNF) levels were analyzed by ELISA. An incidental contextual memory task, with or without an associative encoding instruction, was used to investigate if caregivers have a cognitive reserve prone to rehabilitation. The contextual memory impairment of caregivers was associated with prefrontal and hippocampal cognitive dysfunctions, alterations of the cortisol/DHEA ratio and lower BDNF levels. Even so, the contextual memory impairment could be improved by the associative encoding condition. This study suggests that the cognitive impairments of caregivers are not necessarily irreversible, as indicated by the results obtained for contextual memory, which could be improved despite the ongoing chronic stress and associated hormonal and neurotrophin dysfunctions. Lay summary The support of a relative with Alzheimer's Disease submits the familial caregivers to a chronic stress condition that increases their own risk of cognitive decline. This study suggests that, irrespective to their alterations on cortisol/DHEA ratio and BDNF levels, caregivers have a cognitive reserve that could probably be engaged to limit the negative effects of chronic stress on cognition.

Cognitive remediation: potential novel brain-based treatment for bipolar disorder in children and adolescents

Bipolar disorder (BD) is among the most impairing psychiatric disorders affecting children and adolescents, despite our best psychopharmacological and psychotherapeutic treatments. Cognitive remediation, defined as a behavioral intervention designed to improve cognitive functions so as to reduce psychiatric illness, is an emerging brain-based treatment approach that has thus far not been studied in pediatric BD. The present article reviews the basic principles of cognitive remediation, describes what is known about cognitive remediation in psychiatric disorders, and delineates potential brain/behavior alterations implicated in pediatric BD that might be targets for cognitive remediation. Emerging data show that cognitive remediation may be useful in children and adults with schizophrenia, ADHD, and anxiety disorders, and in adults with BD. Potential targets for cognitive remediation in pediatric BD include face processing, response inhibition, frustration, and cognitive flexibility. Further study is warranted to determine if cognitive remediation for these targets, or others, may serve as a novel, brain-based treatment for pediatric BD.

The neurocognitive functioning in bipolar disorder: a systematic review of data

BACKGROUND

During the last decades, there have been many different opinions concerning the neurocognitive function in Bipolar disorder (BD). The aim of the current study was to perform a systematic review of the literature and to synthesize the data in a comprehensive picture of the neurocognitive dysfunction in BD.

METHODS

Papers were located with searches in PubMed/MEDLINE, through June 1st 2015. The review followed a modified version of the recommendations of the Preferred Items for Reporting of Systematic Reviews and Meta-Analyses statement.

RESULTS

The initial search returned 110,403 papers. After the deletion of duplicates, 11,771 papers remained for further evaluation. Eventually, 250 were included in the analysis.

CONCLUSION

The current review supports the presence of a neurocognitive deficit in BD, in almost all neurocognitive domains. This deficit is qualitative similar to that observed in schizophrenia but it is less severe. There are no differences between BD subtypes. Its origin is unclear. It seems it is an enduring component and represents a core primary characteristic of the illness, rather than being secondary to the mood state or medication. This core deficit is confounded (either increased or attenuated) by the disease phase, specific personal characteristics of the patients (age, gender, education, etc.), current symptomatology and its treatment (especially psychotic features) and long-term course and long-term exposure to medication, psychiatric and somatic comorbidity and alcohol and/or substance abuse.