The brain-adipocyte-gut network: Linking obesity and depression subtypes

Area of Science:

• Neuroscience
• Psychiatry
• Metabolic Disorders

Background:

• Major depressive disorder (MDD) and obesity are significant global health issues.
• Obesity is a known risk factor for MDD, and MDD can increase obesity risk.
• The relationship is complex, with distinct unidirectional links observed in different MDD subtypes.

Purpose of the Study:

• To explore the distinct pathophysiological pathways linking MDD and obesity based on MDD subtypes.
• To examine the role of the psycho-immune neuroendocrine (PINE) network in these associations.
• To identify factors influencing these relationships, including behavioral and biomolecular changes.

Main Methods:

• Systems biology approach analyzing the psycho-immune neuroendocrine (PINE) network.
• Examination of distinct MDD subtypes: general MDD and MDD with atypical features (MDD-AF).
• Consideration of obesity-dependent dysregulation in inflammatory, neuroendocrine, and gut microbiome systems.

Main Results:

• Obesity promotes MDD, while MDD-AF is characterized by weight gain and obesity.
• Obesity-associated depression involves PINE dysfunction augmented by obesity-related network dysregulation.
• Depression-associated obesity in MDD-AF stems from behavioral issues like hypersensitivity to rejection, leading to energy imbalance.

Conclusions:

• The relationship between MDD and obesity is subtype-specific, not simply bidirectional.
• A systems biology framework, particularly the PINE network, is crucial for understanding these links.
• Further research into these complex pathophysiological networks is recommended, considering factors like sex, age, and psychological stress.