Obesity and Depression: Common Link and Possible Targets

Area of Science:

• Neuroscience
• Metabolic Disorders
• Psychiatry

Background:

• Depression is a leading cause of disability, often exacerbated by metabolic conditions like obesity.
• Obesity is associated with depression, particularly abdominal adiposity and poor diet quality.
• The interplay between obesity and depression presents complex challenges for treatment.

Purpose of the Study:

• To review the intricate links between obesity and depression.
• To identify potential therapeutic targets for disrupting this relationship.
• To synthesize current research on the biological mechanisms connecting these conditions.

Main Methods:

• Literature review of research output from PubMed and Scopus.
• Analysis of studies investigating hormonal and microbial influences.
• Examination of neurobiological pathways involved in mood and appetite regulation.

Main Results:

• Obesity and depression share bidirectional links, with depressed individuals showing a higher tendency to gain weight.
• Adipokines (adiponectin, resistin, leptin), ghrelin, and gut microbiota are implicated in the obesity-depression axis.
• Gut microbiota influences CNS activity, impacting mood and cognition, while neuroinflammation is linked to chronic depression.

Conclusions:

• The gut microbiota-brain axis is a critical mediator in the relationship between obesity and depression.
• Hormonal factors and neurotransmitter systems (monoamines, GLP-1) are key players in regulating mood and appetite.
• Obesity-induced neuroinflammation may contribute to persistent depression and cognitive deficits.