Current Behavioral Neuroscience Reports最新文献

Purpose of review: This review provides an overview of the neurobiological mechanisms underlying opioid use disorder (OUD) drawing from genetic, functional and structural magnetic resonance imaging (MRI) research.

Recent findings: Preliminary evidence suggests an association between OUD and specific variants of the DRD2, δ-opioid receptor 1 (OPRD1) and μ-opioid receptor 1 (OPRM1) genes. Additionally, MRI research indicates functional and structural alterations in striatal and corticolimbic brain regions and pathways underlying reward, emotion/stress and cognitive control processes among individuals with OUD.

Summary: Individual differences in genetic and functional and structural brain-based features are correlated with differences in OUD severity and treatment outcomes, and therefore may potentially one day be used to inform OUD treatment selection. However, given the heterogeneous findings reported, further longitudinal research across different stages of opioid addiction is needed to yield a convergent characterization of OUD and improve treatment and prevention.

Purpose of review: While rates of other medical illnesses have declined over the past several decades, rates of suicide have increased, particularly among adolescents. Prior research on biological underpinnings of suicide risk has remained limited. In this review, we describe a recent model conceptualizing suicide as a failure of biological responses to acute stress. According to this model, youth who fail to mount an adaptive stress response following exposure to a stressor are at acute risk for suicide.

Recent findings: Although much more research is needed, early evidence suggests that abnormal biological responses to acute stress, such as altered autonomic nervous system activity and altered hypothalamic-pituitary-adrenal axis function, may underlie risk for suicide, particularly during the transition to adolescence.

Summary: Overall, initial evidence supports a link between biological responses to acute stress and suicide risk. However, future work that incorporates makers of other biological and environmental systems will sharpen our understanding of who is at suicide risk and when this risk is highest.

Purpose of review: This review summarizes recent literature linking Alzheimer's disease (AD) and late life depression (LLD). It describes shared neurobiological features associated with both conditions, as well as factors that may increase resilience to onset and severity of cognitive decline and AD. Finally, we pose a number of future research directions toward improving detection, management, and treatment of both conditions.

Recent findings: Epidemiological studies have consistently shown a significant relationship between LLD and AD, with support for depression as a prodromal feature of AD, a risk factor for AD, and observation of some shared risk factors underlying both disease processes. Three major neurobiological features shared by LLD and AD include neurodegeneration, disruption to cerebrovascular functioning, and increased levels of neuroinflammation. There are also potentially modifiable factors that can increase resilience to AD and LLD, including social support, physical and cognitive engagement, and cognitive reserve.

Summary: We propose that, in the context of depression, neurobiological events, such as neurodegeneration, cerebrovascular disease, and neuroinflammation result in a brain that is more vulnerable to the consequences of the pathophysiological features of AD, lowering the threshold for the onset of the behavioral presentation of AD (i.e., cognitive decline and dementia). We discuss factors that can increase resilience to AD and LLD, including social support, physical and cognitive engagement, and cognitive reserve. We conclude with a discussion of future research directions.

Purpose of review: To summarize the current literature on the effects of cannabinoids in humans and to discuss the existing literature on the sex- and gender-related differences in the effects of cannabinoids.

Recent findings: Cannabis and its constituent cannabinoids are associated with risk of addiction, cognitive deficits and mood/psychotic disorders. Preclinical and emerging clinical data suggest greater sensitivity to the effects of cannabinoids in women.

Summary: Cannabis is one of the most commonly used drugs with increasing rates of use. Women in particular may be at a greater risk of adverse outcomes given the previously described "telescoping effect" of substance use in women. Human data examining the sex- and gender-related differences in the effects of cannabinoids and factors underlying these differences are very limited. This represents a critical gap in the literature and needs to be systematically examined in future studies.

Purpose of review: Neurobiological studies of tobacco/nicotine use examining genetic, molecular, functional, and behavioral correlates have improved our understanding of nicotine/tobacco dependence and have informed treatment. Recent work extending previously established findings and reporting novel methodologies and discoveries in preclinical and human studies are reviewed.

Recent findings: Recent work in preclinical models has focused on the differential roles of nicotinic receptor subtypes and nicotine's effects on neural systems beyond cortico-striatal dopaminergic pathways, and utilizing advanced methodologies such as pharmacogenetics, optogenetics and rodent fMRI to identify targets for treatment. Likewise, human neuroimaging studies have identified molecular and functional dynamic shifts associated with tobacco/nicotine use that further inform treatment.

Summary: Nicotine/tobacco use is associated with widespread neural adaptations that are persistent and function to maintain addiction. The continued identification of genetic, molecular, neural, and behavioral endophenotypes related to nicotine/tobacco use, dependence, and addiction will facilitate the development and delivery of personalized treatment.