The indirect effect of peer problems on adolescent depression through nucleus accumbens volume alteration

Abstract

Literature suggests that neurobiological factors such as brain structure play an important role in linking social stress with depression in adolescence. We aimed to examine the role of subcortical volumetric alteration in the association between peer problems as one type of social stress and adolescent depression. We hypothesized that there would be indirect effects of peer problems on adolescent depression through subcortical volumetric alteration. Seventy eight adolescents with major depressive disorder (MDD) (age mean [SD] = 14.9 ± 1.5, 56 girls) and 47 healthy controls [14.3 ± 1.4, 26 girls]) participated in this study. High-resolution structural T1 images were collected using the Siemens 3T MR scanner. Subcortical volumes were segmented using the Freesurfer 6.0 package. Peer problems were assessed using the Peer-Victimization Scale and the Bullying-Behavior Scale. There was a significant indirect effect of peer problems on adolescent depression through nucleus accumbens (NAcc) volume alteration, but not through the amygdala and hippocampal volumes. This result supported our model, which stated that peer problems have indirect effects through subcortical volumetric alteration (i.e., increased NAcc volume) on adolescent depression. Our finding suggests that altered NAcc volume may serve as a pathway, through which peer problems as one type of social stressor contribute to adolescent depression. Adolescents experience peer problems (e.g., involvement in bully-victim problems) as they devote more time and effort to peer relationships 1. The mean prevalence rates of traditional bullying and cyberbullying involvement were approximately 35% and 15% across 80 studies 2. These peer problems such as being a bully and a victim are considered to be major social stressors, which are known to be related to important adolescent public health issues 3. For example, youth who were bullies and victims showed higher rates of concurrent depression 3 and reported to having long-term adverse effects with greater rates of adulthood depression and suicidality 4. A recent study showed that the prevalence rates of both peer problems and depression remained high in 2015, or even increased compared to those in 2005 5 , indicating that the associations between peer problems and adolescent depression may continue to affect significant public health problems. To ameliorate such public health problems associated with peer relational problems and adolescent depression, other factors should be considered. It has been suggested that neurobiological factors (e.g., brain structure and function) 6 may play an important role in linking social stress with adolescent depression. Furthermore, adolescence is a developmental period for remodeling brain structures and increasing neural plasticity in response to social stress 7. Brain structure may dramatically change in order to adapt to different social and emotional stresses (e.g., problematic peer relations such as bullying involvement) that frequently occur during adolescence. Brain structure alter...

Amygdala size varies with stress perception

“…The putamen is involved in distinct brain functions - such as learning, cognitive functioning, or reward ( Ghandili and Munakomi, 2020 ) - previous reports from our group have already shown hypertrophy in sensorimotor corticostriatal circuits, which is accompanied by a shift to habit-behavior strategies ( Soares et al, 2012 ). The nucleus accumbens gray matter increases have been linked to anxiety ( Kühn et al, 2011 ; Lee et al, 2020 ), being also identified as a biomarker for treatment-responders ( Burkhouse et al, 2020 ). Nonetheless, the residual effect observed in all these regions, that were not confirmed in our FreeSurfer analysis, preclude any conclusion on relevant associations between the volumes of these brain regions and perceived stress scores.…”

Larger bilateral amygdalar volumes are associated with affective loss experiences

“…Sex‐specific differences are conceivable given the high density of sex steroid receptors in the nucleus accumbens (Goldstein et al., 2001): In male mammals, stress exposure and stress‐induced anhedonia have been linked to increased spine density, dendritic hypertrophy, and larger volumes of the nucleus accumbens (Bessa et al., 2013; Warren et al., 2014). In human adolescents of both sexes, larger nucleus accumbens volumes have been related to peer problems, but interactions with sex have not been probed (Lee et al., 2020). In a neuroimaging study with women, bilateral ventral striatal activations have been decreased by grieving for an AL (Najib et al., 2004).…”

“…Chronic stress has also been related to structural changes in the rat dorsal striatum paralleling a behavioral bias toward habit (Dias‐Ferreira et al., 2009). In human neuroimaging studies, reduced dorsal striatal volumes have been associated with long‐term occupational stress (Blix et al., 2013; Savic, 2015) and early life stress (Cohen et al., 2006), and enlarged nucleus accumbens volumes mediated the link between peer problems and adolescent depression (Lee et al., 2020).…”

“…Anxiety and depression have been linked to enlarged amygdalar volumes (De Bellis et al., 2000; Frodl et al., 2002, 2003; Schienle et al., 2011), and to reduced hippocampal and thalamic volumes (Arnone et al., 2012; Hettema et al., 2012; McKinnon et al., 2009; Moon et al., 2015; Nugent et al., 2013). There is also some evidence that anxiety and depression are associated with increased nucleus accumbens volumes (Günther et al., 2018; Kühn et al., 2011; Lee et al., 2020), and with dorsal striatal volume alterations (i.e., reductions in MDD (Ancelin et al., 2019; Bora et al., 2012) and enlargements in GAD (Hilbert et al., 2015; Liao et al., 2013, 2014)). However, hardly anything is known about the effects of AL on subcortical structures in healthy subjects.…”

Parenting and Offspring Brain Development: What Do We Know?

“…For example, prefrontal regions develop the most slowly in the brain, and therefore may be sensitive to developmental influences from childhood through early adulthood, 7 when the prefrontal cortex (PFC) is more fully mature (Dahl, 2004;Hensch, 2004;Luby et al, 2019). While we suspect that parenting has a highly influential effect on offspring brain development, we recognize that a range of other intertwined factors, such as socioeconomic status (Whittle et al, 2017), adverse events outside the parent-child relationship (Luby et al, 2019), and other interpersonal factors such as peer relationships (Lee et al, 2020) are likely influential as well.…”