Your phone is definitely the cause of your menty b, researchers warn

Excessive screen time may increase the risk of depressive symptoms, particularly in young girls, due to its effect on their sleep.

Depression is a common psychological condition that affects roughly 5% of adults, with depression being one of the leading causes of illness among adolescents, according to the World Health Organization (WHO).

WHO estimates that roughly one in seven (14%) of 10 to 19-year-olds experience mental health conditions.

These illnesses “remain largely unrecognized and untreated,” WHO says. This may be due to the lack of understanding surrounding how and why these illnesses emerge.

Researchers have just published a new study that tracked over 4,800 Swedish students aged between 12 and 16 to obtain data surrounding sleep quality and quantity, depressive symptoms, and screen time usage.

This data was collected at three different stages over the course of a year to examine how excessive screen time may hinder a user's sleep quality, which, in turn, leads to depressive symptoms.

They found that increased device use caused “deteriorated sleep,” and excessive screen time postponed sleep, causing users to fall asleep later.

Many studies have demonstrated that blue light, the light emitted from electronic device screens, has a negative effect on users' sleep.

While blue light is effective during the day, says Harvard Medical School, it can suppress the secretion of melatonin, the hormone that helps you fall asleep.

Blue light emitted from screens can also disrupt your circadian rhythm, the body's internal clock, tricking the body into thinking it's in a wakeful period.

“Screen time was also found to postpone sleep times towards later hours – disrupting multiple aspects of the human sleep-wake cycle at once.”

Researchers found that excessive screen time had a “direct adverse effect on depression after twelve months” in boys.

However, the study found that depressive effects in young girls were “mediated through sleep disturbances.”

This means that depressive episodes were made worse in girls when their sleep was interrupted, delayed, or the quality was poor.

Researchers found that sleep, or lack thereof, could explain the connection between screen time and depression in young girls about half (38% to 57%) of the time.

“In this study, we found that adolescents who reported longer screen times also developed poorer sleep habits over time. In turn, this led to increased depression levels, especially among girls."

Their findings seem to suggest that less screen time is healthier, as encouraged recently by the Swedish Public Health Agency, which states that young people should use no more than two to three hours of screen time per day.

The results imply that if young people, particularly young women, used their devices less, then depressive symptoms in this demographic would most likely decrease.