Among 3,431 youth in Fujian Province, China, 28.6% reported suicidal ideation in the past year and 25.9% reported frequent nightmares. Childhood trauma was linked to suicidal ideation partly through nightmare frequency, which accounted for about 4% of the total effect. Sex did not significantly moderate this pathway. Treating nightmares may help reduce suicidal ideation in youth with a history of childhood trauma, regardless of sex.
Rumination, a repetitive self-focused thinking style common in depression, is linked to abnormalities in the default mode network (DMN) of the brain. This study used a novel continuous-state paradigm to directly induce rumination or distraction in healthy participants across three MRI scanners. Results showed that during rumination, connectivity within the DMN generally decreased compared to distraction. Specifically, connectivity increased between the core and medial temporal lobe subsystems and decreased between the core and dorsal medial prefrontal cortex subsystem, as well as within the medial temporal lobe subsystem. Behavioral measures of rumination negatively correlated with connectivity between the core and dorsal medial prefrontal cortex subsystems, suggesting that rumination involves altered interactions among DMN components.
A meta-analysis of 14 functional connectivity studies (10 with seeds in the default mode network, involving 170 meditators and 163 controls) found that meditation is linked to increased connectivity within the default mode network and between the default mode network and the somatomotor network, and to decreased connectivity between the default mode network and the frontoparietal and ventral attention networks. Highly experienced meditators showed a more robust pattern of decreased within-default-mode-network connectivity and increased between-network connectivity. These neural interactions may help explain meditation's effectiveness in clinical interventions for physical and mental disorders.