Young women are the demographic most likely to develop smartphone addiction, according to a landmark study into obsessive phone use - involving 50,000 people across the world.
The researchers, who issued an online survey to people aged 18-90 in nearly 200 countries, found that a third of the global population used their phones in an addictive manner.
Another surprising finding was the country where unhealthy smartphone use is most prevalent.
Researchers found that citizens of some South Asian countries, like the Philippines and Malaysia, are most likely to develop smartphone addiction, even more than the US.
Experts say the extent of the international problem is a serious concern for multiple nations' mental health.
A study of nearly 200 countries found that 29 to 31 percent of the globe is at risk of becoming addicted to their phones
Previous studies have linked above-average smartphone use to a range of mental health problems, including sleep problems, obsessive compulsive disorder (OCD), depression and anxiety.
In the new study, by experts at McGill University in Canada and Harvard University, 50,423 participants in 195 countries filled out a questionnaire about their phone habits known as the Smartphone Addiction Scale.
The majority of the participants - 64 percent - were female, and the average age was 39.
The survey was composed of 10 statements that participants rated from 1 (strongly disagree) to 6 (strongly agree), for a total score ranging from 10 to 60.
The questionnaire featured statements such as, 'I have a hard time concentrating in class while doing assignments or while working due to smartphone use.'
Young women are more likely to have a cell phone addiction than men, the study found, due to socializing more and using phones as a coping mechanism for depression and anxiety
The most common statement participants agreed with was: 'I use my smartphone longer than I intend.'
A score between 31 and 33, the team said, would indicate a smartphone addiction. Based on this, the sample found that 29 to 31 percent of the globe is at risk.
Though the US is not named in the study, that global figure suggests millions of Americans could be addicted to their phones.
The researchers found that young women under age 40 were more likely to develop the problem, compared to men of the same age and older adults.
The team said this could be because women tend to use their phones more for social purposes, such as texting, which can make phone usage a more consistent habit.
They also said that women 'generally have higher rates of depression and anxiety,' which could lead them to doomscroll or use their phones as a distraction.
Additionally, the data looked closely at the 41 countries that had at least 100 participants and found that phone addiction was more common in Southeast Asian countries.
The Philippines had the highest score, with 34.47 points, with Malaysia following closely behind at 34.05 points.
European countries scored the lowest, however, with the Czech Republic taking the bottom spot at 27.66 points. Switzerland came in at 27.88 points, while Portugal had 28.07.
The researchers said it's largely unclear why Southeast Asian countries had the highest rates of cell phone addiction, though it's likely that young people in these countries face greater pressure to keep in contact with friends and family.
The team said that more research is needed to determine why certain countries had higher rates than others.
The study was published last week in the International Journal of Mental Health and Addiction.