Default mode and salience network alterations in suicidal and non-suicidal self-injurious thoughts and behaviors in adolescents with depression

Abstract

Suicidal ideation (SI) and non-suicidal self-injury (NSSI) are two distinct yet often co-occurring risk factors for suicide deaths in adolescents. Elucidating the neurobiological patterns that specifically characterize SI and NSSI in adolescents is needed to inform the use of these markers in intervention studies and to develop brain-based treatment targets. Here, we clinically assessed 70 adolescents—49 adolescents with depression and 21 healthy controls—to determine SI and NSSI history. Twenty-eight of the depressed adolescents had a history of SI and 29 had a history of NSSI (20 overlapping). All participants underwent a resting-state fMRI scan. We compared groups in network coherence of subdivisions of the central executive network (CEN), default mode network (DMN), and salience network (SN). We also examined group differences in between-network connectivity and explored brain-behavior correlations. Depressed adolescents with SI and with NSSI had lower coherence in the ventral DMN compared to those without SI or NSSI, respectively, and healthy controls (all ps < 0.043, uncorrected). Depressed adolescents with NSSI had lower coherence in the anterior DMN and in insula-SN (all ps < 0.030, uncorrected), and higher CEN–DMN connectivity compared to those without NSSI and healthy controls (all ps < 0.030, uncorrected). Lower network coherence in all DMN subnetworks and insula-SN were associated with higher past-month SI and NSSI (all ps < 0.001, uncorrected). Thus, in our sample, both SI and NSSI are related to brain networks associated with difficulties in self-referential processing and future planning, while NSSI specifically is related to brain networks associated with disruptions in interoceptive awareness.

Advancing a temporal framework for understanding the biology of nonsuicidal self- injury: An expert review

“…Together, many of these regions also contribute to the salience and default mode networks. A recent study found that in a sample of adolescents, patients with depression and NSSI demonstrated reduced connectivity at rest within the salience and default mode networks relative to patients with depression but no NSSI and healthy controls (Ho et al, 2021). A strength of this study is the use of both clinical and healthy controls, which suggests that findings may be unique to NSSI rather than due to general psychopathology.…”

Neuroimaging Studies of Nonsuicidal Self-Injury in Youth: A Systematic Review

“…Clinical characteristics of the included samples were diverse, with one study including only BPD patients and another only depressed individuals [ 26 , 35 ]. Psychiatric comorbidity was common among individuals who reported NSSI.…”

“…Only one study employed a network-based approach and found diminished coherence between the default mode and salience networks and higher connectivity between the central executive and default-mode networks [ 26 ]. They also reported an association between higher past-month NSSI and lower coherence in the default mode and insula salience networks [ 26 ].…”

“…The insula, a component of the salience network and closely related to the limbic system [ 62 ], was found to be altered in individuals with NSSI [ 26 , 27 , 33 , 36 , 37 , 43 ]. This region is responsible for encoding negative emotions, attention modulation, interoception, and pain perception [ 63 ].…”

“…In this study, electromyography objectively identified a greater intensity of facial expressions in the NSSI group, despite no differences in self-reported affect, suggesting a suppression or avoidance of the emotional response [ 27 ]. Moreover, limited emotion awareness was associated with altered facial mask processing [ 29 ] and interoceptive awareness deficits with diminished coherence in the default mode and the insula salience networks [ 26 ]. The link between dissociation and NSSI is well established in the literature [ 64 ].…”