Loneliness and depression dissociated on parietal-centered networks in cognitive and resting states

Abstract

Background Perceived loneliness, an increasingly prevalent social issue, is closely associated with major depressive disorder (MDD). However, the neural mechanisms previously implicated in key cognitive and affective processes in loneliness and MDD still remain unclear. Such understanding is critical for delineating the psychobiological basis of the relationship between loneliness and MDD. Methods We isolated the unique and interactive cognitive and neural substrates of loneliness and MDD among 27 MDD patients (mean age = 51.85 years, 20 females), and 25 matched healthy controls (HCs; mean age = 48.72 years, 19 females). We assessed participants' behavioral performance and neural regional and network functions on a Stroop color-word task, and their resting-state neural connectivity. Results Behaviorally, we found greater incongruence-related accuracy cost in MDD patients, but reduced incongruence effect on reaction time in lonelier individuals. When performing the Stroop task, loneliness positively predicted prefrontal-anterior cingulate-parietal connectivity across all participants, whereas MDD patients showed a decrease in connectivity compared to controls. Furthermore, loneliness negatively predicted parietal and cerebellar activities in MDD patients, but positively predicted the same activities in HCs. During resting state, MDD patients showed reduced parietal-anterior cingulate connectivity, which again positively correlated with loneliness in this group. Conclusions We speculate the distinct neurocognitive profile of loneliness might indicate increase in both bottom-up attention and top-down executive control functions. However, the upregulated cognitive control processes in lonely individuals may eventually become exhausted, which may in turn predispose to MDD onset.

Cognitive and Neural Correlates of Loneliness and Wisdom during Emotional Bias

“…Depression emerged as a significant predictor only in younger adults but not when considering all ages. Several other studies show a significant correlation between depression and loneliness (Cacioppo, Hughes, et al 2006;Qualter et al 2010;Fried et al 2015;Bhatti and ul Haq 2017;Shao et al 2019); here, we confirm this relationship only in younger adults, perhaps because our overall lifespan sample consisted of healthy participants with no or low-level depressive symptoms.…”

“…To the best of our knowledge, this is one of the largest sample EEG studies in the literature related to loneliness (Somerville et al 2006, Cacioppo et al 2009, Kanai et al 2012, Spithoven et al 2017, Shao et al 2019. Notably, prior studies of loneliness have rarely included relevant covarying factors of both social network score and wisdom; our study brings these subjective constructs together under one framework.…”

Chronic Loneliness: Neurocognitive Mechanisms and Interventions

“…2). Alterations in the underlying brain circuits have been associated with detrimental effects of loneliness in various functional domains, which appear to be distinct from the consequences of depression [144] and social anxiety [84]. Therapy outcomes may be improved when interventions focus on multiple functional domains and the related neural targets.…”

Chronic loneliness: neurocognitive mechanisms and interventions

“…Figure 2). Alterations in the underlying brain circuits have been associated with detrimental effects of loneliness in various functional domains, which appear to be distinct from the consequences of depression [98] and social anxiety [66]. Therapy outcomes may be improved when interventions focus on multiple functional domains and the related neural targets.…”