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Early life stress (ELS) is a risk factor for the development of depression in adolescence; the mediating neurobiological mechanisms, however, are unknown. In this study, we examined in early pubertal youth the associations among ELS, cortisol stress responsivity, and white matter microstructure of the uncinate fasciculus and the fornix, two key frontolimbic tracts; we also tested whether and how these variables predicted depressive symptoms in later puberty. A total of 208 participants (117 females; M age = 11.37 years; M Tanner stage = 2.03) provided data across two or more assessment modalities: ELS; salivary cortisol levels during a psychosocial stress task; diffusion magnetic resonance imaging; and depressive symptoms. In early puberty there were significant associations between higher ELS and decreased cortisol production, and between decreased cortisol production and increased fractional anisotropy in the uncinate fasciculus. Further, increased fractional anisotropy in the uncinate fasciculus predicted higher depressive symptoms in later puberty, above and beyond earlier symptoms. In post hoc analyses, we found that sex moderated several additional associations. We discuss these findings within a broader conceptual model linking ELS, emotion dysregulation, and depression across the transition through puberty, and contend that brain circuits implicated in the control of hypothalamic-pituitary-adrenal axis function should be a focus of continued research.
PURPOSE OF REVIEW - Given the challenges achieving recommended glycemic targets in youth with type 1 diabetes (T1D), providers may consider recommending carbohydrate-restricted diets (CRDs) to optimize glycemic control. The goal of the present review is to describe relevant literature on the potential medical and psychosocial benefits and risks of CRDs in youth with T1D.
RECENT FINDINGS - Limited data exist on the effects of CRDs in pediatric populations. Findings from studies with youth and adults are mixed; some indicate that CRDs may be associated with desirable medical outcomes, such as improved glycemic control and reduced HbA1c, which may contribute to positive psychological outcomes such as reduced diabetes distress and depressive symptoms. Others suggest that CRDs may also be associated with detrimental outcomes, including mineral deficiencies and suboptimal growth, and dietary restriction has been linked to greater diabetes distress, disordered eating, and diabetes management. More research is needed to evaluate benefits and risks of CRDs in youth. Providers should exercise caution when discussing CRDs with youth and families, particularly when considering CRDs for youth at elevated risk for eating disordered behavior.
BACKGROUND - Life purpose in acute low back pain patients is not well described in published literature.
METHODS/PURPOSE - We used linear regression models to describe the relationship of life purpose with perceived functional disability and depression in persons with acute low back pain (N = 42) participating in a randomized clinical trial to prevent transition to chronic low back pain.
RESULTS - In our predominantly female sample (81.8%) with a mean age of 53 years (SD = 11.6 years), 52% worked full-time. Adjusting for age, gender, and working status, life purpose was a significant correlate of depression (p = .007). For every 10-unit increase in life purpose score, the estimated depression score decreased by almost 2.5 points. A significant relationship between life purpose and perceived functional disability was not identified.
CONCLUSION - Life purpose likely is a modifiable risk factor for depression in acute low back pain patients.
Experimental studies indicate that perinatal light exposure has enduring effects on affective behaviors in rodents; however, insufficient research has explored this hypothesis in humans. We examined photoperiod (i.e., day length) metrics during maternal pregnancy in relation to lifetime depression in the longitudinal Nurses' Health Study (NHS) and NHS II. 160,723 participants reported birth date and birth state (used to derive daily photoperiod based on published mathematical equations), and clinician-diagnosed depression and antidepressant use throughout adulthood. Logistic regression was used to estimate odds ratios (OR) (and 95% confidence intervals [CI]) for depression (defined as clinician diagnosis and antidepressant use) across quintiles of two exposures during maternal pregnancy: 1) total photoperiod (total number of daylight hours) and 2) differences between minimum/maximum photoperiod; each trimester of pregnancy was examined separately. Total photoperiod during maternal pregnancy was not associated with depression overall or by trimester of pregnancy. However, larger differences between minimum/maximum photoperiod during maternal pregnancy were related to lower odds of depression (multivariable [MV]-adjusted OR: 0.86, 95% CI: 0.83, 0.90 comparing extreme quintiles of exposure; p-trend<0.0001); this association appeared specific to the second trimester of pregnancy (MV-adjusted p-trends = 0.03, <0.0001, and 0.3 across the three trimesters, respectively). In addition, birth at higher latitude (where larger differences in minimum/maximum photoperiod exist) was associated with a significant reduction in the lifetime risk of depression. These findings are consistent with an emerging hypothesis in which perinatal light exposure may influence risk of depression, and they might be understood through the conceptual framework of adaptive developmental plasticity.
Copyright © 2018 Elsevier Ltd. All rights reserved.
Active coping is an adaptive stress response that improves outcomes in medical and neuropsychiatric diseases. To date, most research into coping style has focused on neurotransmitter activity and little is known about the intrinsic excitability of neurons in the associated brain regions that facilitate coping. Previous studies have shown that HCN channels regulate neuronal excitability in pyramidal cells and that HCN channel current (I ) in the CA1 area increases with chronic mild stress. Reduction of I in the CA1 area leads to antidepressant-like behavior, and this region has been implicated in the regulation of coping style. We hypothesized that the antidepressant-like behavior achieved with CA1 knockdown of I is accompanied by increases in active coping. In this report, we found that global loss of TRIP8b, a necessary subunit for proper HCN channel localization in pyramidal cells, led to active coping behavior in numerous assays specific to coping style. We next employed a viral strategy using a dominant negative TRIP8b isoform to alter coping behavior by reducing HCN channel expression. This approach led to a robust reduction in I in CA1 pyramidal neurons and an increase in active coping. Together, these results establish that changes in HCN channel function in CA1 influences coping style.
© 2018 International Society for Neurochemistry.
BACKGROUND - Parent-child interactions set the stage for child mental health and development. Given that maternal depressive symptoms are associated with poorer observed caregiving behaviors, examining potential cognitive mediators is important for identifying mechanisms underlying the intergenerational transmission of risk and possible targets for intervention.
METHODS - We assessed depressive symptoms and levels of self-focus and psychological distancing from infant-centered verbal narratives obtained from 54 mothers, and examined caregiving behaviors in a structured interaction with their six-month-old infants.
RESULTS - Higher depressive symptoms were associated with pronoun use in narratives (i.e., greater "I" and reduced "we" use), reflecting increased self-focus and psychological distancing. Further, increased self-focus was associated with lower levels of caregiver warmth, and mediated the association between depressive symptoms and caregiving warmth.
LIMITATIONS - This observational study does not allow for causal interpretations.
CONCLUSION - These findings suggest that the cognitive styles associated with depression interfere with the caregiving relationship, affecting behavior in parent-child interactions that may increase the risk for the intergenerational transmission of depression.
Copyright © 2018 Elsevier B.V. All rights reserved.
OBJECTIVES - To describe the frequency of co-occurring newly acquired cognitive impairment, disability in activities of daily livings, and depression among survivors of a critical illness and to evaluate predictors of being free of post-intensive care syndrome problems.
DESIGN - Prospective cohort study.
SETTING - Medical and surgical ICUs from five U.S. centers.
PATIENTS - Patients with respiratory failure or shock, excluding those with preexisting cognitive impairment or disability in activities of daily livings.
INTERVENTIONS - None.
MEASUREMENTS AND MAIN RESULTS - At 3 and 12 months after hospital discharge, we assessed patients for cognitive impairment, disability, and depression. We categorized patients into eight groups reflecting combinations of cognitive, disability, and mental health problems. Using multivariable logistic regression, we modeled the association between age, education, frailty, durations of mechanical ventilation, delirium, and severe sepsis with the odds of being post-intensive care syndrome free. We analyzed 406 patients with a median age of 61 years and an Acute Physiology and Chronic Health Evaluation II of 23. At 3 and 12 months, one or more post-intensive care syndrome problems were present in 64% and 56%, respectively. Nevertheless, co-occurring post-intensive care syndrome problems (i.e., in two or more domains) were present in 25% at 3 months and 21% at 12 months. Post-intensive care syndrome problems in all three domains were present in only 6% at 3 months and 4% at 12 months. More years of education was associated with greater odds of being post-intensive care syndrome free (p < 0.001 at 3 and 12 mo). More severe frailty was associated with lower odds of being post-intensive care syndrome free (p = 0.005 at 3 mo and p = 0.048 at 12 mo).
CONCLUSIONS - In this multicenter cohort study, one or more post-intensive care syndrome problems were present in the majority of survivors, but co-occurring problems were present in only one out of four. Education was protective from post-intensive care syndrome problems and frailty predictive of the development of post-intensive care syndrome problems. Future studies are needed to understand better the heterogeneous subtypes of post-intensive care syndrome and to identify modifiable risk factors.
Dysregulated fear memory can lead to a broad spectrum of anxiety disorders. The brain systems underlying fear memory are manifold, with the hippocampus being prominently involved by housing fear-related spatial memories as engrams, which are created and stored through neural changes such as synaptic plasticity. Although metabotropic glutamate (mGlu) receptors contribute significantly to both fear behavior and hippocampal synaptic plasticity, the relationship between these two phenomena has not been fully elucidated. Here, we report that contextual fear extinction induces a novel form of metaplasticity mediated by mGlu5 at the hippocampal SC-CA1 synapse. Further, blockade of mGlu5 prevents both contextual fear extinction and expression of this metaplasticity. This form of metaplasticity was absent in a mouse model of MECP2-duplication syndrome, corresponding to a complete deficit in extinction learning. These findings suggest that mGlu5-dependent metaplasticity within the hippocampus may play a critical role in extinction of contextual fear.
BACKGROUND - People with Alzheimer's disease (AD) report pain less frequently and receive less pain medication than people without AD. Recent studies have begun to elucidate how pain may be altered in those with AD. However, potential sex differences in pain responsiveness have never been explored in these patients. It is unclear whether sex differences found in prior studies of healthy young and older individuals extend to people with AD.
OBJECTIVE - The purpose of this study was to examine sex differences in the psychophysical response to experimental thermal pain in people with AD.
METHODS - Cross-sectional analysis of 14 male and 14 female age-matched (≥65 years of age, median = 74) and AD severity-matched (Mini-Mental State Exam score <24, median = 16) communicative people who completed thermal psychophysics.
RESULTS - There was a statistically significant main effect of sex for both temperature and unpleasantness ratings that persisted after controlling for average and current pain (mixed-effects general liner model: temperature: p = 0.004, unpleasantness: p < 0.001). Females reported sensing mild pain and moderate pain percepts at markedly lower temperatures than did males (mild: Cohen's d = 0.72, p = 0.051, moderate: Cohen's d = 0.80, p = 0.036). By contrast, males rated mild and moderate thermal pain stimuli as more unpleasant than did females (mild: Cohen's d = 0.80, p = 0.072, moderate: Cohen's d = 1.32, p = 0.006). There were no statistically significant correlations of temperature with perceived unpleasantness for mild or moderate pain (rs = 0.29 and rs = 0.20 respectively, p > 0.05).
CONCLUSIONS - Results suggest experimental pain-related sex differences persist in older adults with AD in a different manner than those previously demonstrated in cognitively intact older adults. These findings could potentially aid in developing targeted pain management approaches in this vulnerable population. Further studies are warranted to replicate the findings from this pilot work.