Growing up near busy roads linked to higher risk of depression and anxiety

Living near busy roads may increase the risk of developing depression or anxiety, according to a large new study published in Environmental Research.

Traffic noise is an unavoidable part of modern city life. Cars, buses, and trains generate constant background sound that many learn to tune out. But scientists have long suspected that this noise may still affect the body, even when one believes they have adapted to it.

Previous research has highlighted that traffic noise can disturb sleep, raise stress levels, and increase the risk of heart disease. In recent years, attention has turned to the effects on mental health.

However, most earlier studies on noise and mental health have focused on middle-aged or older adults. Hence, the researchers behind the Finnish study wanted to understand whether noise exposure during key developmental years might influence the risk of mental health disorders later on.

Led by Yiyan He from the University of Oulu, Finland, the research team accessed nationwide health and population registers. They analyzed data from 114,353 individuals born between 1987 and 1998 who were living in the Helsinki metropolitan area in 2007. At the start of the study, participants were between 8 and 21 years old. The researchers then followed them until 2016, tracking who received a diagnosis of depression or anxiety in specialist healthcare.

Traffic noise levels were estimated for each participant’s home address, including changes if they moved. The researchers focused mainly on road traffic noise and calculated average sound levels over the entire day, with extra weight given to evening and night-time noise, when individuals are more sensitive to sound. They also accounted for many other factors that could influence mental health, such as family background, parental mental illness, neighborhood disadvantage, air pollution, and access to green space.

Over the follow-up period, about one in ten participants received a diagnosis of depression or anxiety by early adulthood. The study found a clear pattern: higher traffic noise exposure was linked to higher risk. For every 10-decibel increase in road traffic noise, the risk of depression rose by about 5 percent, and the risk of anxiety rose by about 4 percent. While these increases may sound small, He and his team noted that noise exposure affects large numbers of people, making the overall public health impact potentially significant.

Importantly, the risk began to rise at around 53 decibels—a level close to the noise limits recommended by the World Health Organization for residential areas. Night-time noise showed similar effects, supporting the idea that disrupted sleep may play a role.

The study also found differences between groups. The link between noise and anxiety was stronger in males than in females. The association with anxiety was also more pronounced among those whose parents did not have diagnosed mental disorders, suggesting that environmental stressors may be especially influential when family risk is lower.

“Sleep disturbance and stress response have been proposed as key mechanisms underlying the association between traffic noise exposure and the risk of depression and anxiety. Traffic noise has been associated with insomnia symptoms … which are identified as risk factors for depression. In addition, traffic noise exposure has been shown to induce annoyance and heightened physiological stress responses,” He and colleagues explained.

The researchers caution that their study does not prove that traffic noise directly causes depression or anxiety, only demonstrating an association. The study also focused on more severe cases diagnosed in specialist care, meaning milder cases treated by general doctors were not included. In addition, the researchers could not measure noise exposure at schools or workplaces, or how well homes were insulated against sound.

The study, “Residential exposure to traffic noise and incidence of depression and anxiety from childhood through adulthood: a Finnish register study,” was authored by Yiyan He, Marius Lahti-Pulkkinen, Johanna Metsälä, Jaana I. Halonen, Jouko Miettunen, Jules Kerckhoffs, Marko Kantomaa, Eero Kajantie, Sylvain Sebert, and Anna Pulakka.