# The Bidirectional Relationship Between Myocardial Infarction and Depression: Risk Factors, Mechanisms, and Interventions

## TL;DR

This paper explores how heart attacks and depression influence each other, sharing risk factors and biological mechanisms, and suggests ways to treat them together.

## Contribution

The paper emphasizes treating MI and depression as a unified condition using combined evidence rather than separate studies.

## Key findings

- Myocardial infarction and depression are linked through shared mechanisms like inflammation and the heart–brain axis.
- Common risk factors include age, lifestyle, and genetics, which affect the combined condition's prognosis.
- Current treatments include psychotherapy, exercise, and pharmacological interventions targeting both diseases.

## Abstract

Myocardial infarction (MI) and depression exhibit a bidirectional relationship, in which patients with MI are more susceptible to depression, and individuals with depression face a heightened risk of MI. The two diseases are intricately intertwined via the heart–brain axis. Sex, age, lifestyle, social background, comorbidities, and genetics contribute to and affect the prognosis of this combined condition. Mechanisms involving the autonomic nervous system (ANS), hypothalamic–pituitary–adrenal (HPA) axis, inflammation, thrombosis, tryptophan metabolism, renin–angiotensin–aldosterone system (RAAS), endothelial dysfunction, microRNAs, and gut microbiota, as components of the heart–brain axis, have been implicated in the pathological link between MI and depression. This review outlines the common risk factors and potential mechanisms underlying this bidirectional relationship. It treats the comorbidities of MI and depression as a unified condition, relying on evidence from clinical trials and experimental studies that directly address both diseases together rather than extrapolating from separate studies on MI or depression alone. It also discusses current therapeutic approaches, including non-pharmacological interventions like psychotherapy and exercise, and pharmacological treatments with chemical or natural compounds. Finally, this review identifies significant gaps in the pathophysiology and clinical management of MI with depression, which warrant further investigation.