People with serious psychiatric disorders are far more likely to develop heart disease, diabetes, and other metabolic conditions than the general population, and a new review suggests that shared biological pathways help explain why, according to research published in Cureus.
The review examined the connections between psychiatric illnesses such as schizophrenia, bipolar disorder, and major depression and a cluster of physical health problems known as cardiometabolic disease. That cluster includes obesity, insulin resistance, high blood pressure, and abnormal cholesterol levels. Researchers found that the relationship between mental illness and these physical conditions is not coincidental or explained solely by lifestyle factors.
Several overlapping biological mechanisms appear to connect the two categories of disease. Chronic low-grade inflammation is one of the most consistent links. Elevated inflammatory markers are found in patients with depression and schizophrenia, and those same markers are associated with increased cardiovascular risk. The immune system, in other words, appears to be dysregulated in ways that affect both the brain and the heart.
Dysregulation of the hypothalamic-pituitary-adrenal axis, the system that governs the body's response to stress, is another shared pathway the review identified. Prolonged activation of this system elevates cortisol levels, which over time contributes to weight gain, insulin resistance, and vascular damage. Psychiatric disorders are associated with chronic dysregulation of this axis, creating a sustained physiological stress state even when external circumstances appear stable.
Mitochondrial dysfunction also emerged as a common thread. Mitochondria, the structures inside cells that produce energy, show abnormalities in both psychiatric and metabolic conditions. When mitochondria do not function efficiently, cells throughout the body, including neurons and cardiac muscle cells, are left more vulnerable to damage.
The review noted that some psychiatric medications contribute independently to metabolic risk. Several antipsychotic drugs are associated with significant weight gain and changes in blood sugar regulation. This means that even when psychiatric treatment is successful, it can inadvertently worsen cardiometabolic outcomes if not monitored carefully.
The authors argued for a more integrated approach to treating patients with psychiatric disorders, one that includes routine monitoring of metabolic health markers rather than treating mental and physical health as separate concerns. People with serious mental illness die on average 10 to 20 years earlier than the general population, and cardiovascular disease is the leading cause of that gap.
Understanding the shared biology underlying both categories of illness may eventually point toward treatments that address both simultaneously, rather than requiring patients to navigate separate and often disconnected care systems.
