Yingxue Gao1, Ruohan Feng2, Lihua Zhuo2, Kaili Liang1, Weijie Bao1, Hui Qiu1, Zilin Zhou1, Guoping Huang3, and Xiaoqi Huang1
1Huaxi MR Research Center (HMRRC), Department of Radiology, West China Hospital, Sichuan University, Chengdu, China, 2Department of Radiology, the Third Hospital of Mianyang, Sichuan Mental Health Center, Mianyang, China, Mianyang, China, 3Department of Psychiatry, the Third Hospital of Mianyang, Sichuan Mental Health Center, China, Mianyang, China
Synopsis
The current study investigate functional network
alterations in adolescent MDD using the clustering analysis. We found that adolescents
with MDD showed decreased connectivity between the frontoparietal network (FPN)
and other networks relative to HC. The global connectivity strength of FPN was
negatively correlated with the punishment and academic pressure factors, and
mediated the association between these two stressors and depression. Our
findings suggest that punishment and academic pressure may contribute to the
development of depression in adolescence through dysfunction of the FPN, which
may promote future prevention of adolescent MDD.
Introduction
Adolescence is a critical developmental period
which encompasses many significant changes, including brain growth, biological
and physical changes of puberty, and major social role transitions1.
These changes make some adolescents more susceptible to the effects of
psychosocial stressors and are vulnerable to developing depression2.
Stressful life events are salient risk factors for
MDD in adolescence3. The association between stressful life events
and depressive symptoms or disorders has been consistently reported in both
cross-sectional4 and longitudinal studies5. Neuroimaging
studies found that the ways early life stress affects the brain networks were
similar to those of adult depression6. However, how the life stress
influence the adolescent brain and involve the development of adolescent
depression remain unclear.
In this study, we aim to investigate functional network
alterations in adolescents with MDD and explore the associations among these
functional properties of networks, stressful life events and adolescent
depression.Methods
Participants
and MRI Data Acquisition
We recruited 68 adolescents with MDD and
43 healthy controls (HC) aged from 11 to 18 years old from The Third People's
Hospital of Mianyang, Sichuan. All participants were scanned using a 3.0T MRI
system with a twenty-channel phased-array head coil. The MR data consisted of resting-state
EPI images and T1-weighted anatomical images.
Clinical
measurement
The Hamilton depression scale 24 item
(HAMD-24) and Hamilton Anxiety scale 14 item (HAMA-14) were applied to assess
the symptoms severity of depression and anxiety of all adolescents. Recent negative
life events were measured using the Adolescents Self-Rating Life Events
Checklist (ASLEC), which was utilized to assess the frequency of stressful life
events and stress response intensity over the previous 12 months.
Functional
connectivity analysis
The k-means clustering (k ranged from
2 to 22) was performed to identify functional networks in MDD and HC groups,
respectively. To evaluate the stability of the clustering
solutions, the Dice’s coefficient was computed for each number of clusters. Then
we calculated the weighted degree centrality (DC) for each network to characterize
the global connectivity strength of the networks. The weighted degree
centrality measures the sum of weights or strength from edges (i.e., the
Pearson correlation coefficient) connecting to a network.
Statistical
analysis
The differences of
the degree centrality of networks between MDD and HC groups were investigated
using the ANCOVA with age, gender, IQ and mean FD as covariates. We further
investigated the relationships between DC of group differences and HAMD total
scores and factors in ASLEC using partial correlation analysis. Finally, the
mediation analysis was performed to explore the mediation role of DC
alterations in the associations between factors in ASLEC and depression
diagnosis. The p < 0.05 was set as significance threshold and the Bonferroni
correction was used to correct multiple comparison.Results
The demographic and clinical information of MDD
patients and HC were presented in Table 1. MDD adolescents showed significantly
higher HAMD and HAMD scores, and higher scores of all factors in ASLEC compared
with HC.
The clustering analysis identified fourteen stable and detailed GM functional
networks for both MDD and HC groups (Figure 1). Comparing to HC, adolescents
with MDD showed significantly lower weighted degree centrality of the first
subnetwork of the frontoparietal network (FPN1). The DC of FPN1 was negatively correlated
with the punishment and academic pressure factors of the ASLEC in the MDD group,
and mediated the association between these two stressors and depression after
controlled the effects of the age, gender, IQ and
mean FD (Figure 2). Discussion & Conclusion
Adolescents with MDD showed global hypoconnectivity
of the FPN, a network involved in cognitive
control and emotion regulation7. This result was consistent with previous findings that functional
connectivity abnormalities in adolescent MDD were mainly focused on the
cognitive control network8.
Interestingly, we found that the global
hypoconnectivity of FPN was correlated with increased punishment and academic
stress, and mediated the associations between these two stressors and
depression. These findings suggest that punishment and academic pressure may
contribute to the development of depression in adolescence through dysfunction
of frontoparietal network, which may promote future prevention of adolescent
MDD.Acknowledgements
This study is supported
by grants from 1.3.5 Project for Disciplines of Excellence, West China
Hospital, Sichuan University (ZYJC21041) and Clinical and Translational
Research Fund of Chinese Academy of Medical Sciences (2021-I2M-C&T-B-097).References
1. Sawyer
SM, Azzopardi PS, Wickremarathne D et al. The age of adolescence. The Lancet.
Child & adolescent health. 2018;2(3):223–228.
2. Thapar
A, Collishaw S, Pine DS et al. Depression in adolescence. Lancet.
2012;379:1056–1067.
3. Malhi
GS, Mann JJ. Depression. Lancet. 2018;392(10161):2299-2312.
4. Mileviciute
I, Trujillo J, Gray M et al. The role of explanatory style and negative life
events in depression: A cross-sectional study with youth from a North American
plains reservation. American Indian and Alaska Native Health Research. 2016;20(3):42–58.
5. Asselmann
E, Wittchen H-U, Lieb R, et al. Danger and loss events and the incidence of
anxiety and depressive disorders: a prospective-longitudinal community study of
adolescents and young adults. Psychological Medicine, 2015;45:153–163.
6. Gong Q,
He Y. Depression, neuroimaging and connectomics: a selective overview. Biol
Psychiatry. 2015;77(3):223-235.
7. Marek S,
Dosenbach NUF. The frontoparietal network: function, electrophysiology, and
importance of individual precision mapping. Dialogues Clin Neurosci.
2018;20(2):133-140.
8. Tang S,
Lu L, Zhang L, et al. Abnormal amygdala resting-state functional connectivity
in adults and adolescents with major depressive disorder: A comparative
meta-analysis. EBioMedicine. 2018;36:436-445.