Research paper | Neural pathways of eating disorders

We are happy to share our research work "Development of disordered eating behaviors and comorbid depressive symptoms in adolescence: neural and psychopathological predictors", which has been published in Biological Psychiatry in 2020.

Research summary 

Background & Aims

Eating disorders are common in adolescence and are strongly comorbid with other psychiatric conditions. Yet, knowledge is limited on the aetiological mechanisms and their relationships with the comorbidities. This study aimed to identify neural and psychopathological predictors for the development of disordered eating behaviours and comorbid mental health conditions in adolescence.

Participants & Assessments

Longitudinal assessments of disordered eating behaviours (DEBs; binge-eating, purging and dieting) and comorbid symptoms (depression and generalized anxiety) were measured in 1,386 adolescents from the IMAGEN study. Participants took part in the study at ages 14, 16 and 19. Potential psychopathological predictors investigated were emotional symptoms, conduct problems, hyperactivity/inattention symptoms and peer relationship problems, measured by the Strengths and Difficulty Questionnaire. The neural predictors investigated here were the grey matter volumes of the brain, obtained from Voxel-Based Morphometry analysis on MRI structural neuroimaging.

Design & Analysis

We defined developer groups for each of these symptoms involving participants who did not report symptoms at age 14 but developed symptoms at ages 16/19, and control groups who did not report symptoms at any of the three ages. We compared grey matter volumes and psychopathological differences at age 14 between the developers and controls to identify risk factors.

Results

DEBs and depressive symptoms developed together. Emotional and behavioural problems, including symptoms of attention deficit hyperactivity disorder (ADHD) and conduct disorder (CD), predated the development of both DEBs and depression. Alterations in fronto-striatal brain areas also predated the development of DEBs and depressive symptoms. Specifically, development of binge-eating at ages 16/19 was predicted by higher grey matter volumes in the right putamen/globus pallidus at age 14. On the other hand, development of purging and depressive symptoms was predicted by lower volumes in the medial orbitofrontal, dorsomedial and dorsolateral prefrontal cortices, encompassing the brain’s reward processing and inhibition control systems. Lower grey matter volumes in the orbitofrontal and anterior cingulate cortices mediated the relationship between ADHD and CD symptoms at age 14 and the development of purging and depressive symptoms at later ages.

Conclusion

These findings suggest that alterations in frontal brain circuits are part of the shared aetiology between eating disorders, ADHD, CD and depression and highlight the importance of a transdiagnostic approach to treating these conditions.

Acknowledgements

Sincere thanks to all the participants in the IMAGEN study and the ESTRA study!