Depression may be at the root of many illnesses. A series of large-scale medical studies warns of a "bidirectional vicious cycle" in which conditions such as diabetes and heart disease can seed depression — and depression, in turn, can trigger serious metabolic disease.
A multinational cohort study examining the bidirectional relationship between cardiometabolic multimorbidity (CMM) and depression among middle-aged and older adults in 19 countries found that patients with cardiovascular metabolic diseases — including diabetes, heart disease and stroke — were 1.52 times more likely to develop depression than those without such conditions. The risk rose even more steeply when two or more diseases were present simultaneously.
The reverse pathway is equally striking. People with depression were 1.31 times more likely to later develop CMM. Lifestyle factors linked to depression — reduced physical activity and worsening drinking habits — accounted for 7 to 12 percent of that disease risk.
A large-scale domestic cohort study has produced findings consistent with these results, showing that more severe depressive symptoms are associated with a greater risk of developing metabolic dysfunction-associated steatotic liver disease (MASLD). Women under 45 with depression face a risk increase of up to 20 percent, researchers said.
MASLD is a leading cause of chronic liver disease. Closely linked to metabolic disorders such as obesity, diabetes and hyperlipidemia, it can progress to cardiovascular disease or liver cancer.
A research team led by professors Cho Sung-jun and Kim Eun-su of the psychiatry department and professor Son Won of the gastroenterology department at Kangbuk Samsung Hospital, affiliated with Sungkyunkwan University School of Medicine, analyzed data from 170,981 adults who underwent health checkups at the hospital's comprehensive health screening center between 2003 and 2022.
The team selected participants who showed no fatty liver on ultrasound and had no history of metabolic disease or psychiatric medication use. Participants were divided into three groups based on their scores on the Center for Epidemiologic Studies Depression (CES-D) scale: a normal group (below 8 points), a mild depression group (8 to 15 points) and a depression group (16 points or above). They were then followed for an average of 5.4 years.
The risk of developing fatty liver rose in proportion to the severity of depressive symptoms in both men and women, though the trend was more pronounced in women. Compared with the normal group, men in the mild depression group had a 3 percent higher risk and those in the depression group had a 6 percent higher risk. Among women, the mild depression group showed a 5 percent higher risk, while the depression group showed an 18 percent higher risk.
The association was sharpest among women under 45. Even mild depressive symptoms were linked to a 5 percent higher risk of fatty liver compared with the normal group, while the risk jumped to 20 percent in the depression group.
"Previous research has focused on the surge in metabolic disease risk — including fatty liver — that occurs in postmenopausal women due to declining estrogen levels," said Son, the gastroenterology professor. "This study is the first to use large-scale data to demonstrate that even premenopausal young women with depression can have compromised metabolic health."
Kim, the psychiatry professor, said the findings confirm depression is "not merely a source of psychological distress, but an independent risk factor that disrupts the hormonal and immune systems and threatens overall physical health." He urged patients with depression to undergo proactive screening for liver health and metabolic dysfunction and to pursue early, active management.
kty@heraldcorp.com
