A global depression study from the University of Hong Kong's (HKU) Department of Psychiatry has found that individuals with depression have double the mortality risk compared to non-depressed individuals, with a suicide risk nearly 10 times higher. The research also linked depression to an increased risk of death from conditions like heart disease and diabetes.
This study, encompassing over 10 million depression patients globally and nearly 2.8 billion controls, indicated that timely and effective treatment can significantly reduce the mortality risk in depressed patients by up to 30 percent.
Suicide Risk Nearly 10x Higher Linked to Deaths from Heart Disease/Diabetes
This research, led by the HKU Department of Psychiatry, synthesized data from 268 cohort studies worldwide, involving over 10 million individuals with depression from regions including the US, UK, China (including Hong Kong), Singapore, and South Korea. The findings were published in the authoritative international journal World Psychiatry.
What were the key findings?
- The overall mortality risk for people with depression was twice as high as for those without depression.
- The risk of suicide was nearly 10 times higher.
- There was a significant increase in the risk of death from physical illnesses such as heart disease, diabetes, neurological disorders, endocrine diseases, and cancer among people with depression.
Professor Eric Chen Yu-hai, Chair of Psychiatry at HKUMed, pointed out that depression is associated with various natural causes of death. Unhealthy lifestyle factors like smoking, physical inactivity, poor diet, and insufficient self-management of health may exacerbate these risks.
First Six Months After Diagnosis Most Dangerous with Higher Mortality Risk for Young Women
The research team also discovered that mortality risk fluctuates significantly within the first five years after a depression diagnosis, highlighting the critical importance of early intervention.
Key Time Points:
- First 180 days post-diagnosis: The mortality risk was highest, being 11 times that of non-depressed individuals.
- Depressed women under 25: Their overall mortality risk was about 6 times higher than their non-depressed peers.
- Individuals under 25 and over 60: Showed markedly high suicide risks, at 10 times and 13 timeshigher, respectively.
Depression Subtypes:
- Patients with depression with psychotic symptoms had a 61 percent higher mortality risk.
- Patients with treatment-resistant depression had a 27 percent higher mortality risk.
Drug Treatment Shows Significant Effect, Can Reduce Mortality Risk
Chen emphasized, "Depression is not just an emotional disorder but a major public health issue. Fortunately, it is a treatable condition, and timely, appropriate treatment can save lives." The team believes that if individuals with depression receive effective treatment early, their mortality risk can be significantly reduced. Treatments include:
- Antidepressants: Reduced overall mortality risk by approximately 20 percent.
- Electroconvulsive Therapy (ECT): Reduced mortality risk by nearly 30 percent.
- Depressed patients with physical illnesses: Antidepressants were even more effective, reducing mortality risk by 30 percent.
332 Million People Affected Globally – Early Identification is Crucial
Depression affects over 332 million people globally (4 percent of the population), with profound impacts on both mental and physical health. Chen added, "Regardless of region or development background, depression poses a heavy burden on society. Early identification, continuous treatment, and integrated support are crucial for helping patients recover and extend their healthy lifespan." The research team calls on the public, healthcare professionals, and policymakers to jointly recognize the severity of depression and actively promote early identification and intervention.
