A neurobiological approach to the cognitive deficits of psychiatric disorders

Deficits in brain networks that support cognitive regulatory functions are prevalent in many psychiatric disorders. Findings across neuropsychology and neuroimaging point to broad-based impairments that cross traditional diagnostic boundaries. These dysfunctions are largely separate from the classical symptoms of the disorders, and manifest in regulatory problems in both traditional cognitive and emotional domains. As such, they relate to the capacity of patients to engage effectively in their daily lives and activity, often persist even in the face of symptomatically effective treatment, and are poorly targeted by current treatments. Advances in cognitive neuroscience now allow us to ground an understanding of these cognitive regulatory deficits in the function and interaction of key brain networks. This emerging neurobiological understanding furthermore points to several promising routes for novel neuroscience-informed treatments targeted more specifically at improving cognitive function in a range of psychiatric disorders.

Elevated prefrontal myo-inositol and choline following breast cancer chemotherapy

Breast cancer survivors are at increased risk for cognitive dysfunction, which reduces quality of life. Neuroimaging studies provide critical insights regarding the mechanisms underlying these cognitive deficits as well as potential biologic targets for interventions. We measured several metabolite concentrations using (1)H magnetic resonance spectroscopy as well as cognitive performance in 19 female breast cancer survivors and 17 age-matched female controls. Women with breast cancer were all treated with chemotherapy. Results indicated significantly increased choline (Cho) and myo-inositol (mI) with correspondingly decreased N-acetylaspartate (NAA)/Cho and NAA/mI ratios in the breast cancer group compared to controls. The breast cancer group reported reduced executive function and memory, and subjective memory ability was correlated with mI and Cho levels in both groups. These findings provide preliminary evidence of an altered metabolic profile that increases our understanding of neurobiologic status post-breast cancer and chemotherapy.

Cortisol, cytokines, and hippocampal volume interactions in the elderly

Separate bodies of literature report that elevated pro-inflammatory cytokines and cortisol negatively affect hippocampal structure and cognitive functioning, particularly in older adults. Although interactions between cytokines and cortisol occur through a variety of known mechanisms, few studies consider how their interactions affect brain structure. In this preliminary study, we assess the impact of interactions between circulating levels of IL-1Beta, IL-6, IL-8, IL-10, IL-12, TNF-alpha, and waking cortisol on hippocampal volume. Twenty-eight community-dwelling older adults underwent blood draws for quantification of circulating cytokines and saliva collections to quantify the cortisol awakening response. Hippocampal volume measurements were made using structural magnetic resonance imaging. Elevated levels of waking cortisol in conjunction with higher concentrations of IL-6 and TNF-alpha were associated with smaller hippocampal volumes. In addition, independent of cortisol, higher levels of IL-1beta and TNF-alpha were also associated with smaller hippocampal volumes. These data provide preliminary evidence that higher cortisol, in conjunction with higher IL-6 and TNF-alpha, are associated with smaller hippocampal volume in older adults. We suggest that the dynamic balance between the hypothalamic-pituitary adrenal axis and inflammation processes may explain hippocampal volume reductions in older adults better than either set of measures do in isolation.

Psychosocial predictors of salivary cortisol among older adults with depression

ABSTRACT Background: Previous studies have identified a number of psychosocial risk factors of dysregulated cortisol (frequently referred to as the "stress hormone") among older adults with depression. However, these studies have typically only examined a handful of risk factors at a time and have sometimes yielded inconsistent results. Method: This study aims to address this gap in the literature by simultaneously examining a range of relevant psychosocial predictors of diurnal cortisol among 54 older adults with a depressive disorder. Salivary cortisol was assessed upon awakening, at 5 PM, and at 9 PM across two consecutive days. Participants also completed measures of global psychosocial stress, current psychiatric symptomatology, pervasive distress (e.g. history of past depression), and protective factors (e.g. social support, resiliency, extent to which one has "made sense" of a significant stressor). Results: High levels of current depressive symptoms, psychiatric comorbidities, past depressive episodes, trait anxiety, and poorer ability to make sense of one's stress were found to be associated with flatter (more abnormal) cortisol slopes. However, when all of these variables were entered simultaneously in a multiple regression analysis, only history of past depression and the degree of sense made of stress emerged as unique predictors of cortisol in the model. Conclusions: These findings have important implications for identifying depressed elderly individuals with dysregulated cortisol patterns who may be most at risk for health complications. Treatments that aim to limit the chronicity of depression and help to increase the sense made of stress could potentially have a positive impact on health.

The unique impact of late-life bereavement and prolonged grief on diurnal cortisol

OBJECTIVES

This study expands on previous research by examining the effects of prolonged grief disorder (PGD) symptoms and bereavement on diurnal cortisol patterns above and beyond depressive symptomatology.

METHODS

Drawing on information from 56 depressed older adults, 3 groups were compared: (1) a depressed nonbereaved group, (2) a depressed bereaved without elevated PGD symptoms group, and (3) a depressed bereaved with elevated PGD symptoms group. Multilevel modeling was used to examine differences in diurnal cortisol profiles between these 3 groups, controlling for demographic factors and depressive symptoms.

RESULTS

Results revealed that those who were bereaved had more dysregulated cortisol patterns, but PGD symptomatology seemed to have little effect. Subsidiary analysis with just the bereaved participants suggests that those who were recently widowed may have had greater cortisol dysregulation compared with other bereaved individuals in the sample.

DISCUSSION

These findings suggest that the circumstance of being bereaved may be associated with more dysregulated cortisol, regardless of PGD symptomatology. This pattern of results might reflect greater disturbance in daily routines among bereaved individuals and acute stress in the case of those experiencing the recent loss of a spouse, which leads to disruption in circadian rhythms and the diurnal cycle of cortisol.

Pretreatment cortisol levels predict posttreatment outcomes among older adults with depression in cognitive behavioral therapy

Previous studies suggest that individuals with elevated levels of cortisol (the "stress hormone") could be particularly resistant to treatment for depression. However, most of these studies have been conducted in the context of antidepressant medications, and no study has examined pretreatment cortisol levels as a predictor of treatment outcomes among older adults with depression in cognitive-behavioral therapy (CBT), despite the relevance of this population for such a research question. The current study includes 54 older adults with depression who provided salivary cortisol samples at baseline and completed measures of depression at pretreatment and posttreatment, following a 12-week course of CBT. Structural equation modeling results suggest that those with higher daily outputs of cortisol and flatter diurnal slopes were less likely to benefit from CBT-a finding which if replicated could have important implications for clinical practice and future research.

DSM-5 sleep-wake disorders classification: overview for use in clinical practice

Mental health clinicians should appreciate that sleep is a fundamental human behavior and that inadequate sleep has adverse medical, psychiatric, and psychosocial consequences. Sleep disturbances interact with common mental disorders; the two are mutually exacerbating, and both must be appropriately addressed to ensure optimal outcomes for our patients. Sleep is by the brain, of the brain, and for the brain.

Early exposure to traumatic stressors impairs emotional brain circuitry

Exposure to early life trauma (ELT) is known to have a profound impact on mental development, leading to a higher risk for depression and anxiety. Our aim was to use multiple structural imaging methods to systematically investigate how traumatic stressors early in life impact the emotional brain circuits, typically found impaired with clinical diagnosis of depression and anxiety, across the lifespan in an otherwise healthy cohort. MRI data and self-reported histories of ELT from 352 healthy individuals screened for no psychiatric disorders were analyzed in this study. The volume and cortical thickness of the limbic and cingulate regions were assessed for all participants. A large subset of the cohort also had diffusion tensor imaging data, which was used to quantify white matter structural integrity of these regions. We found a significantly smaller amygdala volume and cortical thickness in the rostral anterior cingulate cortex associated with higher ELT exposure only for the adolescence group. White matter integrity of these regions was not affected. These findings demonstrate that exposure to early life trauma is associated with alterations in the gray matter of cingulate-limbic regions during adolescence in an otherwise healthy sample. These findings are interesting in the context that the affected regions are central neuroanatomical components in the psychopathology of depression, and adolescence is a peak period for risk and onset of the disorder.

Nocturnal rapid eye movement sleep latency for identifying patients with narcolepsy/hypocretin deficiency

IMPORTANCE

Narcolepsy, a disorder associated with HLA-DQB1*06:02 and caused by hypocretin (orexin) deficiency, is diagnosed using the Multiple Sleep Latency Test (MSLT) following nocturnal polysomnography (NPSG). In many patients, a short rapid eye movement sleep latency (REML) during the NPSG is also observed but not used diagnostically.

OBJECTIVE

To determine diagnostic accuracy and clinical utility of nocturnal REML measures in narcolepsy/hypocretin deficiency.

DESIGN, SETTING, AND PARTICIPANTS

Observational study using receiver operating characteristic curves for NPSG REML and MSLT findings (sleep studies performed between May 1976 and September 2011 at university medical centers in the United States, China, Korea, and Europe) to determine optimal diagnostic cutoffs for narcolepsy/hypocretin deficiency compared with different samples: controls, patients with other sleep disorders, patients with other hypersomnias, and patients with narcolepsy with normal hypocretin levels. Increasingly stringent comparisons were made. In a first comparison, 516 age- and sex-matched patients with narcolepsy/hypocretin deficiency were selected from 1749 patients and compared with 516 controls. In a second comparison, 749 successive patients undergoing sleep evaluation for any sleep disorders (low pretest probability for narcolepsy) were compared within groups by final diagnosis of narcolepsy/hypocretin deficiency. In the third comparison, 254 patients with a high pretest probability of having narcolepsy were compared within group by their final diagnosis. Finally, 118 patients with narcolepsy/hypocretin deficiency were compared with 118 age- and sex-matched patients with a diagnosis of narcolepsy but with normal hypocretin levels.

MAIN OUTCOME AND MEASURES

Sensitivity and specificity of NPSG REML and MSLT as diagnostic tests for narcolepsy/hypocretin deficiency. This diagnosis was defined as narcolepsy associated with cataplexy plus HLA-DQB1*06:02 positivity (no cerebrospinal fluid hypocretin-1 results available) or narcolepsy with documented low (≤ 110 pg/mL) cerebrospinal fluid hypocretin-1 level.

RESULTS

Short REML (≤15 minutes) during NPSG was highly specific (99.2% [95% CI, 98.5%-100.0%] of 516 and 99.6% [95% CI, 99.1%-100.0%] of 735) but not sensitive (50.6% [95% CI, 46.3%-54.9%] of 516 and 35.7% [95% CI, 10.6%-60.8%] of 14) for patients with narcolepsy/hypocretin deficiency vs population-based controls or all patients with sleep disorders undergoing a nocturnal sleep study (area under the curve, 0.799 [95% CI, 0.771-0.826] and 0.704 [95% CI, 0.524-0.907], respectively). In patients with central hypersomnia and thus a high pretest probability for narcolepsy, short REML remained highly specific (95.4% [95% CI, 90.4%-98.3%] of 132) and similarly sensitive (57.4% [95% CI, 48.1%-66.3%] of 122) for narcolepsy/hypocretin deficiency (area under the curve, 0.765 [95% CI, 0.707-0.831]). Positive predictive value in this high pretest probability sample was 92.1% (95% CI, 83.6%-97.0%).

CONCLUSIONS AND RELEVANCE

Among patients being evaluated for possible narcolepsy, short REML (≤15 minutes) at NPSG had high specificity and positive predictive value and may be considered diagnostic without the use of an MSLT; absence of short REML, however, requires a subsequent MSLT.

Neuropsychiatric symptoms, apolipoprotein E gene, and risk of progression to cognitive impairment, no dementia and dementia: the Aging, Demographics, and Memory Study (ADAMS)

OBJECTIVE

To examine the relationship of neuropsychiatric symptoms and apolipoprotein E (APOE) ε4 allele status to dementia at baseline and progression to dementia in older adults with and without cognitive impairment, no dementia (CIND).

METHODS

Adults (n = 856) 71 years and older (mean age = 79.15 years), 12.8% ethnic minority and 60.6% women, completed neuropsychological tests and APOE genotyping, and a proxy informant completed the Neuropsychiatric Inventory.

RESULTS

After adjusting for age and education, neuropsychiatric symptoms and APOE ε4 were independently associated with CIND and dementia status at baseline (compared with cognitively normal). Further, neuropsychiatric symptoms predicted progression to dementia at 16- to 18-month follow-up among participants with CIND at baseline; the presence of these symptoms decreased the risk of progression from normal to CIND or dementia at 36 to 48 months.

CONCLUSION

Findings provide cross-sectional and longitudinal support for the role of neuropsychiatric symptoms in the prediction of cognitive impairment, particularly dementia. APOE ε4, although important, may be a less robust predictor. This investigation highlights the importance of behavioral symptoms, such as neuropsychiatric symptom status or frequency/severity, as predictors of future cognitive decline.

Sleep disturbance in pediatric PTSD: current findings and future directions

Many studies have provided strong evidence of a fundamental and complex role for sleep disturbances in adult posttraumatic stress disorder (PTSD). Investigations of adult PTSD using subjective and objective measures document sleep architecture abnormalities and high prevalence of sleep disordered breathing, periodic limb movement disorder, nightmares, and insomnia. PTSD treatment methods do appear to significantly improve sleep disturbance, and also studies suggest that treatments for sleep disorders often result in improvements in PTSD symptoms. Further, the most recent evidence suggests sleep abnormalities may precede the development of PTSD. Given the importance of sleep disorders to the onset, course, and treatment of adult PTSD, examination of sleep disturbances far earlier in the life course is imperative. Here we review the literature on what we know about sleep disturbances and disorders in pediatric PTSD. Our review indicates that the extant, empirical data examining sleep disturbance and disorders in pediatric PTSD is limited. Yet, this literature suggests there are significantly higher reports of sleep disturbances and nightmares in children and adolescents exposed to trauma and/or diagnosed with PTSD than in non-trauma-exposed samples. Sleep questionnaires are predominantly employed to assess sleep disorders in pediatric PTSD, with few studies utilizing objective measures. Given the important, complex relationship being uncovered between adult PTSD and sleep, this review calls for further research of sleep in children with PTSD using more specific subjective measures and also objective measures, such as polysomnography and eventually treatment trial studies.

The long-term impact of early adversity on late-life psychiatric disorders

Early adversity is a strong and enduring predictor of psychiatric disorders including mood disorders, anxiety disorders, substance abuse or dependence, and posttraumatic stress disorder. However, the mechanisms of this effect are not well understood. The purpose of this review is to summarize and integrate the current research knowledge pertaining to the long-term effects of early adversity on psychiatric disorders, particularly in late life. We explore definitional considerations including key dimensions of the experience such as type, severity, and timing of adversity relative to development. We then review the potential biological and environmental mediators and moderators of the relationships between early adversity and psychiatric disorders. We conclude with clinical implications, methodological challenges and suggestions for future research.

Therapeutic approaches to age-associated neurocognitive disorders

The United Nations projects that the number of individuals with dementia in developed countries alone will be approximately 36,7 million by the year 2050. International recognition of the significant emotional and economic burden of Alzheimer's disease has been matched by a dramatic increase in the development of pharmacological and nonpharmacological approaches to this illness in the past decade. Changing demographics have underscored the necessity to develop similar approaches for the remediation of the cognitive impairment associated with more benign syndromes, such as mild cognitive impairment (MCI) and age-associated cognitive decline (AACD). The present article aims to provide an overview of the most current therapeutic approaches to age-associated neurocognitive disorders. Additionally, it discusses the conceptual and methodological issues that surround the design, implementation, and interpretation of such approaches.

MR spectroscopy for assessment of memantine treatment in mild to moderate Alzheimer dementia

OBJECTIVES

Magnetic Resonance Spectroscopy (MRS) may provide a precise and reliable assessment of the extent and severity of neural tissue loss caused by various diseases. In particular, the N-Acetyl Aspartate (NAA) and Creatine (Cr) ratio has been found to be an indicator of the degree of neuronal loss in Alzheimer's disease (AD). Memantine is thought to benefit the AD brain by stabilizing the NMDA receptors on neurons in turn reducing excitotoxicity. Despite its effectiveness in treating moderate to severe AD, memantine has not had similar success in the treatment of mildly demented AD patients. The objective of this study was to test whether memantine would slow or prevent the loss of neurons in mild to moderate AD patients.

METHODS

A double-blind placebo-controlled study was designed to measure the effect of a year-long course of memantine in patients with a probable AD diagnosis with mild to moderate dementia. The primary outcome measure was stipulated to be change in MRS NAA/Cr ratio in inferior parietal cortex in memantine relative to the placebo treatment condition. The secondary outcome measures were changes in cognitive and function scale scores.

RESULTS

This pilot study failed to demonstrate a benefit of memantine on the primary outcome measure, the inferior parietal NAA/Cr ratio, or the secondary outcome measures.

CONCLUSIONS

More studies are needed to determine the effect of memantine on regions of the brain significantly affected by AD pathology.

Prefrontal cortex and executive function impairments in primary breast cancer

OBJECTIVES

To examine differences in prefrontal-executive function between breast cancer (BC) survivors with and without a history of chemotherapy treatment compared with healthy control women and to determine the associations between prefrontal cortex deficits and behavioral impairments, as well as certain demographic and disease variables.

DESIGN

Observational study.

SETTING

University-based research facility.

PARTICIPANTS

Twenty-five women with BC who had received chemotherapy, 19 women with BC who had not received chemotherapy, and 18 healthy female controls, all matched for age and other demographic variables.

RESULTS

Women with BC demonstrated significantly reduced activation in the left middle dorsolateral prefrontal cortex and premotor cortex compared with healthy controls. The chemotherapy group also demonstrated significantly reduced left caudal lateral prefrontal cortex activation and increased perseverative errors and reduced processing speed compared with the other 2 groups. Reduced left caudal lateral prefrontal cortex activation was significantly correlated with higher disease severity and elevated subjective executive dysfunction in the chemotherapy-treated women. Older age and lower educational level were associated with increased executive function impairment in the chemotherapy group.

CONCLUSIONS

These findings provide further evidence of neurological impairment associated with primary BC irrespective of treatment history. The left caudal lateral prefrontal region may be particularly vulnerable to the effects of chemotherapy and/or disease severity and may represent a novel biomarker of subjective executive dysfunction in chemotherapy-treated women. Furthermore, negative effects of chemotherapy on brain function may be exacerbated by such factors as increased age and lower educational level.

Gender differences in sexual behaviors of AD patients and their relationship to spousal caregiver well-being

OBJECTIVES

Little is known about gender differences in sexuality among community-dwelling heterosexual couples in which one partner has Alzheimer's disease (AD). Few studies have examined gender differences in specific sexual behaviors or their associations with caregiver well-being. This study evaluated the impact of gender differences on intimacy and sexual satisfaction in marital relationships in which one partner has AD.

METHOD

Baseline measures were collected from 162 AD patients and their partners enrolled in a multi-site study between 2001 and 2009 to evaluate gender differences in measures of intimacy, caregiver well-being, and patient sexual behaviors.

RESULTS

While over 70% of all patients initiated physically intimate activities (i.e., kissing, hugging, and intercourse), most did not initiate intercourse specifically. Female caregivers reported higher levels of stress and depressive symptoms than male caregivers (p < 0.01). Satisfaction with intimacy was significantly associated with fewer stress and depressive symptoms in female caregivers (r = -0.29, p < 0.01). Caregiver gender, satisfaction with intimacy, and caring for a patient with mild AD were significant predictors of caregiver depressive symptoms (p's < 0.05).

CONCLUSION

The majority of couples dealing with AD reported engaging in intimacy, suggesting its importance in the relationship. Female caregivers who reported less sexual satisfaction reported more frequent stress and depressive symptoms. Caregiver gender, satisfaction with intimacy, and the AD patient's level of cognitive functioning significantly contributed to caregiver well-being. Gender-specific therapies to address patient sexual difficulties and caregiver well-being could potentially maintain or improve the marital relationship.

Design considerations for characterizing psychiatric trajectories across the lifespan: application to effects of APOE-ε4 on cerebral cortical thickness in Alzheimer's disease

Characterization of developmental trajectories across the lifespan is integral to understanding the prodromal course of many neuropsychiatric illnesses and the significant risk factors for disease onset or unfavorable outcomes. However, the standard experimental designs used in psychiatric research are not ideal for this purpose. The authors review the limitations of the most commonly employed designs in studies that make developmental or lifespan inferences in psychiatry: cross-sectional, single-cohort longitudinal, and unstructured multicohort longitudinal designs. Cross-sectional studies completely confound within- and between-subject sources of variation and hence rely on the presence of parallel trajectories and negligible sampling and age cohort differences for making valid developmental inferences. Delineating trajectories of within-individual change over substantial periods of time requires data covering long age spans that often cannot be covered using single-cohort longitudinal designs. Unstructured multicohort longitudinal designs are a commonly used alternative that can cover a longer age span in a shorter interval than necessary for a single-cohort design. However, the impact of cohort and sampling effects is often minimized or ignored in unstructured multicohort longitudinal designs. The authors propose that structured multicohort longitudinal designs are a particularly viable and underutilized class of designs in psychiatry that represents a significant improvement over cross-sectional designs and unstructured multicohort longitudinal designs for making developmental inferences while being more practical to implement than single-cohort longitudinal designs. As an example of this approach, the authors analyze changes in entorhinal cortex thickness in Alzheimer's disease in relation to APOE-ε4 genotype.

Epidemiology of restless legs syndrome: a synthesis of the literature

Restless legs syndrome (RLS) has gained considerable attention in the recent years: nearly 50 community-based studies have been published in the last decade around the world. The development of strict diagnostic criteria in 1995 and their revision in 2003 helped to stimulate research interest on this syndrome. In community-based surveys, RLS has been studied as: 1) a symptom only, 2) a set of symptoms meeting minimal diagnostic criteria of the international restless legs syndrome study group (IRLSSG), 3) meeting minimal criteria accompanied with a specific frequency and/or severity, and 4) a differential diagnosis. In the first case, prevalence estimates in the general adult population ranged from 9.4% to 15%. In the second case, prevalence ranged from 3.9% to 14.3%. When frequency/severity is added, prevalence ranged from 2.2% to 7.9% and when differential diagnosis is applied prevalence estimates are between 1.9% and 4.6%. In all instances, RLS prevalence is higher in women than in men. It also increases with age in European and North American countries but not in Asian countries. Symptoms of anxiety and depression have been consistently associated with RLS. Overall, individuals with RLS have a poorer health than non-RLS but evidence for specific disease associations is mixed. Future epidemiological studies should focus on systematically adding frequency and severity in the definition of the syndrome in order to minimize the inclusion of cases mimicking RLS.

Iatrogenic bismuth toxicity associated with inadvertent long term De-Noltab ingestion

A prolonged course of oral tripotassium dicitratobismuthate (De-Noltab) was administered to an elderly woman. The patient developed extrapyramidal neurological symptoms and subsequently sustained accidental fracture of the right neck of the femur before bismuth toxicity was identified. The parkinsonian features that presented in this patient were thought to be possibly related to the accumulation of bismuth in the basal ganglia as a result of the long term ingestion of tripotassium dicitratobismuthate.

Prolonged treatment with the drug should be discouraged and repeat prescriptions should always be queried.

A method to combine cognitive and neurophysiological assessments of the elderly

BACKGROUND

The development of better treatments for brain diseases of the elderly will necessitate more sensitive and efficient means of repeatedly assessing an individual's neurocognitive status.

AIM

To illustrate the development of an assessment combining episodic memory and working memory tasks with simultaneous electroencephalography and evoked potential (EP) brain function measures.

METHODS

Data from matched groups of elderly subjects with mildly impaired episodic verbal memory on neuropsychological tests and those with no objective signs of impairment were used for scale development. An exploratory multivariate divergence analysis selected task performance and neurophysiological variables that best recognized impairment. Discriminant validity was then initially assessed on separate impaired and unimpaired groups.

RESULTS

Decreased response accuracy and parietal late positive component EP amplitude in the episodic memory task best characterized impaired subjects. Sensitivity in recognizing impairment in the validation analysis was 89% with 79% specificity (area under the curve = 0.94). Retest reliability was 0.89 for the unimpaired and 0.74 for the impaired validation groups.

CONCLUSION

These promising initial results suggest that with further refinement and testing, an assessment combining cognitive task performance with simultaneous neurofunctional measures could eventually provide an important benefit for clinicians and researchers.