Neural correlates of anxious distress in depression: A neuroimaging study of reactivity to emotional faces and resting-state functional connectivity

Psychedelic Research for Alcohol Use Disorder with Comorbid Major Depressive Disorder: An Unmet Need

PURPOSE OF REVIEW

In this narrative review, we discuss evidence for psilocybin- and LSD-assisted treatment of alcohol use disorder (AUD) and major depressive disorder (MDD). We describe limitations of psychedelic research and posit methodological considerations when designing a trial in patients with both disorders.

RECENT FINDINGS

In AUD, a growing evidence base for psilocybin treatment shows a promising beneficial and sustained effect on measures of drinking frequency. In MDD, a recent meta-analysis has demonstrated that psilocybin therapy provides a large and consistent reduction in depressive symptoms compared to no treatment. Co-occurrence of MDD and AUD is quite prevalent, and this comorbidity exacerbates symptomatology of the two individual disorders and complicates their treatment. Theoretically, patients presenting with both AUD and MDD would benefit from an integrated therapy that could treat MDD and AUD simultaneously. We believe that more research into the efficacy of psilocybin in patients with both AUD and MDD is warranted and justified.

Co-occurrence of depressive and anxious symptoms and their influence on self-rated health: a national representative survey among Chinese older adults

OBJECTIVES

The prevalence of the co-occurrence of depressive and anxious symptoms (CO) and their influence on perceived overall health were not clear in community dwelling Chinese older adults. The aims of the study were to investigate the prevalence of CO and to explore its influence on self-rated health (SRH).

METHOD

This study included 12301 individuals aged ≥65 years from the 2018 wave of the Chinese Longitudinal Healthy Longevity Survey (CLHLS), a nationally representative survey of older adults in mainland China. Participants received face-to-face interviews and assessments of depressive symptoms and anxious symptoms via 10-item of the Center for Epidemiologic Studies Depression Scale (CES-D-10) and 7-item Generalized Anxiety Disorder Questionnaire (GAD-7), respectively. SRH was measured by self-reported. A logistic regression model was used to examine the association between CO and SRH after adjusting for confounding variables.

RESULTS

The average age was 83.4 (SD: 11.0) years and there were 6576 (53.5%) females. The age- and sex-standardized prevalence of depressive symptoms only (DSO) was 38.6%, anxious symptoms only (ASO) was 1.5%, and CO was 10.8%. Compared with those without depressive and anxious symptoms, the older adults with DSO or ASO were more likely to have significant influence on SRH. And particularly, CO was likely to produce the greatest decrement in the level of SRH.

CONCLUSION

CO was not rare in Chinese older adults nationwide. The older adults having CO had increased risk for lower level of SRH than having DSO or ASO. More attention should be given to CO among the older adults.

Social Dysfunction and Neural Processing of Emotional Valence Across Depressive and Anxiety Disorders

Social dysfunction is common across psychiatric disorders, including depressive and anxiety disorders. Both disorders have been associated with negative biases in socioaffective neural processing, which may impact responses to social stimuli. This study aims to determine whether social dysfunction across these psychiatric disorders is indeed coupled to altered neural processing of negative and positive valenced emotional stimuli and whether a common neurobiological correlate can be identified. An implicit emotional faces functional magnetic resonance imaging task was used to measure brain activation in response to emotional stimuli in participants with depression (N = 46), anxiety (N = 45), comorbid depressive and anxiety disorders (N = 57), and healthy controls (N = 52). Social dysfunction was indexed using five items of the World Health Organisation Disability Assessment Schedule-2.0 (i.e., perceived social disability) and with the De Jong-Gierveld Loneliness scale (LON; i.e., perceived loneliness). Higher perceived social disability scores were associated with greater brain activation in the left angular gyrus in response to sad emotional faces across all participants but did not correlate with responses to overall negative (sad, angry, and fearful) or positive (happy) emotional faces. No interaction effect of diagnosis was observed for the finding. Perceived loneliness scores did not correlate with brain activation to emotional faces. Taken together, perceived social disability across persons with and without depressive and/or anxiety disorders converges specifically on sad emotional processing of the left angular gyrus, suggesting a potential common neurobiological correlate for social dysfunction.

TRPC4/5 inhibitors: Phase I results and proof of concept studies

Transient receptor potential canonical (TRPC) ion channels are expressed in areas of the brain responsible for processing emotion and mood and have been implicated in the pathophysiology of internalizing disorders such as major depressive disorder and anxiety disorders. This review outlines the rationale for targeting TRPC ion channels for drug development, with specific focus on TRPC4 and TRPC5. We provide preclinical evidence that the lack of TRPC4 and TRPC5 channels or its pharmacological inhibition attenuate fear and anxiety without impairing other behaviors in mice. We also report on clinical studies of BI 1358894, a small molecule inhibitor of TRPC4/5 ion channels, demonstrating reduced psychological and physiological responses to induced anxiety/panic-like symptoms in healthy volunteers. Furthermore, we highlight an imaging study that investigated the acute effects of BI 1358894 and showed reduced activation in several brain regions involved in emotional processing. We conclude that these findings demonstrate a critical role for TRPC4 and TRPC5 in emotional processing, even though it remains an open question if the biological signatures of TRPC4/5 inhibition reported here translate into clinical efficacy and indicate that a TRPC4/5 inhibitor might provide a more effective treatment of internalizing disorders.

Brain structural and functional abnormalities in affective network are associated with anxious depression

BACKGROUND

Anxious depression (AD) is a common subtype of major depressive disorder (MDD). Neuroimaging studies of AD have revealed inconsistent and heterogeneous brain alterations with the use of single-model methods. Therefore, it is necessary to explore the pathogenesis of AD using multi-model imaging analyses to obtain more homogeneous and robust results.

METHODS

One hundred and eighty-two patients with MDD and 64 matched healthy controls (HCs) were recruited. Voxel-based morphometry (VBM) was used to estimate the gray matter volume (GMV) of all subjects. The GMV differences between the AD and non-anxious depression (NAD) participants were used as regions of interest (ROIs) for subsequent resting state functional connectivity (rs-FC) analyses. Correlation analysis was used to evaluate the associations between clinical symptoms and abnormal function in specific brain areas.

RESULTS

Decreased GMV in the medial frontal gyrus (MFG) and the superior frontal gyrus (SFG) was observed in the AD group compared to the NAD group. Taking the MFG and SFG as ROIs, the rs-FC analysis revealed decreased FC between the left SFG and left temporal pole and between the left SFG and right MFG in the AD group compared to the NAD group. Finally, the FC between the left SFG and left temporal pole was negatively correlated with HAMD-17 scores in the AD group.

CONCLUSION

By combining the GMV and rs-FC models, this study revealed that structural and functional disruption of the affective network may be an important pathophysiology underlying AD. The structural impairment may serve as the foundation of the functional impairment.

Dynamic reconfigurations of brain networks in depressive and anxiety disorders: The influence of antidepressants

Major Depressive Disorder (MDD) and anxiety disorders are highly comorbid recurrent psychiatric disorders. Reduced dynamic reconfiguration of brain regions across subnetworks may play a critical role underlying these deficits, with indications of normalization after treatment with antidepressants. This study investigated dynamic reconfigurations in controls and individuals with a current MDD and/or anxiety disorder including antidepressant users and non-users in a large sample (N = 207) of adults. We quantified the number of subnetworks a region switched to (promiscuity) as well as the total number of switches (flexibility). Average whole-brain (i.e., global) values and subnetwork-specific values were compared between diagnosis and antidepressant groups. No differences in reconfiguration dynamics were found between individuals with a current MDD (N = 49), anxiety disorder (N = 46), comorbid MDD and anxiety disorder (N = 55), or controls (N = 57). Global and sensorimotor network (SMN) promiscuity and flexibility were higher in antidepressant users (N = 49, regardless of diagnosis) compared to non-users (N = 101) and controls. Dynamic reconfigurations were considerably higher in antidepressant users relative to non-users and controls, but not significantly altered in individuals with a MDD and/or anxiety disorder. The increase in antidepressant users was apparent across the whole brain and in the SMN when investigating subnetworks. These findings help disentangle how antidepressants improve symptoms.

Specific alterations of resting-state functional connectivity in the triple network related to comorbid anxiety in major depressive disorder

The brain's default mode network (DMN) and the executive control network (ECN) switch engagement are influenced by the ventral attention network (VAN). Alterations in resting-state functional connectivity (RSFC) within this so-called triple network have been demonstrated in patients with major depressive disorder (MDD) or anxiety disorders (ADs). This study investigated alterations in the RSFC in patients with comorbid MDD and ADs to better understand the pathophysiology of this prevalent group of patients. Sixty-eight participants (52.9% male, mean age 35.3 years), consisting of 25 patients with comorbid MDD and ADs (MDD + AD), 20 patients with MDD only (MDD) and 23 healthy controls (HCs) were investigated clinically and with 3T resting-state fMRI. RSFC utilizing a seed-based approach within the three networks belonging to the triple network was compared between the groups. Compared with HC, MDD + AD showed significantly reduced RSFC between the ECN and the VAN, the DMN and the VAN and within the ECN. No differences could be found for the MDD group compared with both other groups. Furthermore, symptom severity and medication status did not affect RSFC values. The results of this study show a distinct set of alterations of RSFC for patients with comorbid MDD and AD compared with HCs. This set of dysfunctions might be related to less adequate switching between the DMN and the ECN as well as poorer functioning of the ECN. This might contribute to additional difficulties in engaging and utilizing consciously controlled emotional regulation strategies.

Dysconnectivity of the brain functional network and abnormally expressed peripheral transcriptional profiles in patients with anxious depression

BACKGROUND

Major depressive disorder (MDD) is a heterogeneous mental disorder, and accompanying anxiety symptoms, known as anxious depression (AD), are the most common subtype. However, the pathophysiology of AD may be distinct in depressed patients without anxiety (NAD) and remains unknown. This study aimed to investigate the relationship between functional connectivity and peripheral transcriptional profiles in patients with AD and NAD.

METHODS

Functional imaging data were collected to identify differences in functional networks among patients with AD (n = 66), patients with NAD (n = 115), and healthy controls (HC, n = 200). The peripheral transcriptional data were clustered as co-expression modules, and their associations with AD, AND, and HC were analyzed. The gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) functional enrichment analyses of the genes in the significant module were performed. Correlation analysis was performed to identify functional network-associated gene co-expression modules.

RESULTS

A network was identified which consisted of 23 nodes and 28 edges that were significantly different among three sample groups. The regions of the network were located in temporal and occipital lobe. Two gene co-expression modules were shown to be associated with NAD, and one of which was correlated with the disrupted network in the AD group. The biological function of this module was enriched in immune regulation pathways.

CONCLUSION

The results suggested that immune-related mechanisms were associated with functional networks in AD.