Good sleep may have a stronger influence on teenagers’ academic performance and social lives than diet, exercise or screen time, according to new research examining the daily factors that shape young people’s well-being.

The findings suggest that sleep could be particularly important for children experiencing symptoms of depression, anxiety or psychotic-like experiences, which have been linked to difficulties at school and in relationships.

Researchers examined data from more than 6,000 children for academic performance and more than 7,000 for social difficulties. The participants were aged between 10 and 13 and were assessed on four lifestyle factors: sleep quality, screen use, physical activity and diet.

Children showing symptoms of mental health difficulties generally performed worse academically and experienced more social problems. However, researchers found that lifestyle habits appeared to explain a significant part of this relationship, with sleep standing out as the most important factor.

“We expected sleep to be important, but we didn’t expect it to stand out so clearly above other lifestyle factors, particularly screen time,” said Jason Smucny, the study’s lead author at the University of California, Davis.

Researchers said poor sleep can cause daytime tiredness, problems with concentration and weaker executive functioning, all of which can make it harder for students to learn, complete schoolwork and perform well in examinations.

Sleep may also affect relationships. Disrupted or inadequate sleep can contribute to irritability and social withdrawal, potentially making it harder for young people to communicate with friends and maintain healthy relationships.

The researchers said their findings point to sleep quality as an important pathway through which early mental health symptoms can affect everyday functioning.

Tara Niendam, the study’s senior author, said parents, teachers and health professionals often concentrate on symptoms such as anxiety and depression, but families are also concerned about how those difficulties affect school performance, friendships and daily activities.

The research suggests that improving sleep routines could be one practical way of supporting young people facing these challenges.

Adolescents have increasingly struggled to get enough sleep, with previous research indicating that teenage sleep levels have declined over recent decades. School demands, social activities, technology use and changing schedules can all interfere with regular sleeping patterns.

The researchers stressed that better sleep cannot address every mental health problem. However, establishing consistent sleep routines may support emotional health and help young people manage the demands of school and social life.

With summer giving students an opportunity to recover from demanding school schedules, the findings highlight the potential importance of using the break to establish healthier and more consistent sleeping habits before the new academic year begins.

Greece is experiencing a sharp rise in West Nile virus infections, with health authorities warning that the mosquito-borne disease is spreading more widely than confirmed case numbers suggest. The country, alongside Italy, has recorded the highest level of virus activity in Europe this season.

Greece’s National Public Health Organisation reported 23 new infections during the past week. Since the start of the transmission season in spring through August 5, the country has confirmed 65 cases. Of those, 54 patients developed severe neurological complications, including encephalitis, meningitis or acute flaccid paralysis, while 11 experienced mild symptoms or no significant effects on the central nervous system.

The outbreak has resulted in six deaths, all involving patients over the age of 65 who suffered severe neurological illness.

Health officials cautioned that the confirmed figures represent only a fraction of the virus’s actual spread. Based on seroepidemiological data, authorities estimate that for every patient diagnosed with serious neurological disease, about 140 other people may have been infected without being diagnosed because they developed mild symptoms or none at all.

The virus continues to circulate across several regions of Greece. Cases have been identified in 25 municipalities covering Attica, Thessaly and Central Macedonia. The highest concentration has been recorded in Attica, where public health officials say transmission has been particularly intense this summer.

Of the 65 confirmed patients, 20 remain in hospital. Twelve are receiving treatment in general wards, while eight are in intensive care units. Thirty-eight patients have been discharged, and one person did not require hospital treatment.

The outbreak is part of a broader rise in West Nile virus activity across Europe. According to the European Centre for Disease Prevention and Control (ECDC), human infections have also been confirmed in Italy, Romania, France, North Macedonia, Spain and Germany through July 29.

The ECDC has identified 49 affected areas across seven European countries. Italy accounts for the largest number, with 30 affected areas, followed by Greece with eight. Romania has four affected areas, while France, North Macedonia and Spain each have two, and Germany has one.

Italy has also reported the highest number of confirmed human infections in Europe this season, with 94 cases. North Macedonia and Spain have each recorded seven cases, Romania has reported five, France two and Germany one.

West Nile virus is transmitted primarily through the bites of infected mosquitoes. Most infected people experience either mild flu-like symptoms or no symptoms at all. In a small proportion of cases, particularly among older adults and people with underlying health conditions, the infection can lead to serious neurological disease.

Public health authorities are urging residents and visitors to reduce mosquito exposure by using insect repellent, wearing protective clothing and eliminating standing water where mosquitoes breed as surveillance and prevention efforts continue throughout the summer.