Most people think that gaining weight is the main reason why mental health problems like depression can lead to diseases such as diabetes.
A new study from the University of Sydney suggests this may not be true. Instead, the real issue may be something much less visible: poor sleep.
The research followed nearly 2,000 young Australians over ten years. The goal was to understand how early mental health problems affect physical health later in life. The participants were in their early 20s at the start and were tracked into their 30s, a time when most people still appear healthy on the outside.
Depression was one of the key factors studied. It is known to affect many aspects of life, including mood, energy, and daily routines. One of the most common but often overlooked effects of depression is disrupted sleep. People with depression may go to bed at different times, wake up at irregular hours, or have difficulty staying asleep.
The study found that these sleep problems were not just short-term issues. Instead, they often continued for years. Over time, this ongoing disruption to sleep patterns was strongly linked to insulin resistance, a condition that can lead to diabetes and heart disease.
What surprised the researchers was that weight gain did not play a major role in this process. Even participants who were not overweight showed signs of metabolic risk if they had long-term sleep disturbances. This challenges the idea that weight is the main link between depression and physical illness.
Insulin resistance can develop quietly, without clear symptoms. It affects how the body handles sugar and energy. If not addressed, it can lead to serious conditions later in life. The study shows that these risks can begin much earlier than people expect.
Professor Ian Hickie, who led the study, said that focusing only on weight may miss an important part of the problem. He explained that sleep and daily routines should be given more attention in mental health care, especially for young adults.
The study also suggests that small changes in daily habits could make a big difference. Regular sleep schedules, exposure to natural light during the day, and reducing bright light at night can help improve sleep quality and support the body’s natural rhythm.
This research is important because it shows that mental and physical health are closely connected. It also highlights a key opportunity for prevention. By improving sleep early, it may be possible to reduce the risk of chronic diseases later in life.
The findings were published in the Journal of Affective Disorders and add to growing evidence that lifestyle factors play a major role in long-term health.
If you care about health, please read studies that scientists find a core feature of depression and this metal in the brain strongly linked to depression.
For more health information, please see recent studies about drug for mental health that may harm the brain, and results showing this therapy more effective than ketamine in treating severe depression.
Source: University of Sydney.
