Respiration pattern variability and related default mode network connectivity are altered in remitted depression

Area of Science:

• Neuroscience
• Psychiatry
• Psychology

Background:

• Existing research indicates a link between respiration and mood in healthy individuals and those with respiratory conditions.
• The study investigates respiration pattern variability (RPV) in individuals with remitted depression during emotional challenge.

Purpose of the Study:

• To determine if remitted depressed individuals exhibit higher RPV when emotionally challenged.
• To explore the relationship between RPV, mood, clinical outcomes, and default mode network connectivity in depression.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used to assess brain activity in 30 individuals with recurrent major depressive disorder (rMDD) and 30 healthy controls (HCs) while inducing sad mood.
• Respiration was monitored using a respiration belt, supplemented by mood questionnaires, daily mood assessments, and a 3-year follow-up.
• RPV was also analyzed in an independent sample of 53 rMDD patients for replication.

Main Results:

• During induced sadness, rMDD patients displayed greater RPV compared to HCs, characterized by increased variability in pause duration and respiration frequency, and a lower expiration-to-inspiration ratio.
• Elevated RPV was associated with lower daily mood and predicted higher depression scores and relapse rates over a 3-year period.
• In rMDD patients, higher respiration frequency showed a positive association with connectivity between the posterior cingulate cortex and the right parahippocampal gyrus.

Conclusions:

• The findings establish a link between RPV, mood, and depression at both behavioral and neural levels.
• Interventions targeting respiration are proposed as a potentially valuable adjunctive therapy for depression treatment.