The United States is currently witnessing a generational shift in mood disorders, with more teenagers and young adults experiencing serious psychological distress than in previous decades. In a study published Wednesday in the Journal of Abnormal Psychology, scientists argue that a lack of sleep, entwined with the rise of digital media, may be to blame.

Drawing from the National Survey on Drug Use and Health, the researchers behind the new study analyzed responses from more than 200,000 adolescents aged 12 to 17 between 2005 and 2017. They also examined data provided by almost 400,000 adults aged 18 and over whose responses were collected from 2008 to 2017. While there was not a significant increase in the percentage of older adults who experienced depression or psychological distress in the mid to late 2000s, the same was not true for adolescents and young adults.

The rate of young adults with suicidal thoughts increased by 47 percent from 2008 to 2017, and the rate of young adults experiencing serious psychological distress increased by 71 percent from 2008 to 2017.

The rate of adolescents reporting symptoms of major depression sometime in the last 12 months increased by 52 percent from 2005 to 2017. Meanwhile, there was a 63 percent rise in the same reporting for young adults between the ages of 18 and 25 from 2009 to 2017.

“More U.S. adolescents and young adults in the late 2010s, versus the mid-200s, experienced serious psychological distress, major depression or suicidal thoughts, and more attempted suicide,” lead author and San Diego State psychology professor Jean Twenge, Ph.D., announced Wednesday. “These trends are weak or non-existent among adults 26 years and over, suggesting a generational shift in mood disorders instead of an overall increase across all ages.”

Only half of people treated for depression find current drugs effective. Flickr / Vansterpartiet

While mood disorder indicators increased among both young men and women, the increases were largest among women. They also found that while young people across most racial and ethnic groups reported depression, the largest increase in reporting mood disorders was done by white Americans and Americans with the highest total family income. The team writes, “this suggests the largest increases in mood disorder outcomes occurred among higher socioeconomic status white women and girls.”

The team cannot say definitively what is driving these changes because survey respondents were not asked to explain why they might be feeling the way they do. However, scientists can make an educated hypothesis: Because the increase in mental health issues was sharpest after 2011 — a period of economic expansion and falling unemployment — Twenge believes the rise is likely linked to cultural changes rather than economic woes or genetics.

Increased use of electronic communication and digital media over the past decade, the team writes, “may have changed modes of social interaction enough to affect mood disorders and suicide-related outcomes.” Previous studies have shown that people who spend more time on social media and less IRL time with others are more likely to be depressed. Cyberbullying is also linked to depression, self-harm, and suicidal thoughts.

“The stronger cohort effect may have occurred because the trend toward digital media had a different impact on individuals depending on their age and developmental stage,” they write. “For example, the time adolescents spent with their friends face-to-face declined between 2009 and 2017, whereas shifts in the frequency of face-to-face social interaction among adults appear to be less pronounced.”

U.S. adolescents are also sleeping less: A recent review of studies found that, since 2000, insomnia became prevalent among 18.5 percent of university students. Its prevalence in the general population, meanwhile, sits closer to 7.4 percent. And the neural link between depression and a lack of sleep is well established.

“Young people can’t change their genetics or the economic situation of the country, but they can choose how they spend their leisure time,” Twenge advises. She recommends that adolescents prioritize their sleep and keep their phones and tablets out of the bedroom. Overall, the professor says, “make sure digital media use doesn’t interfere with activities more beneficial to mental health, such as face-to-face social interaction, exercise, and sleep.”

Abstract:

Drawing from the National Survey on Drug Use and Health (NSDUH; N 611,880), a nationally representative survey of U.S. adolescents and adults, we assess age, period, and cohort trends in mood disorders and suicide-related outcomes since the mid-2000s. Rates of major depressive episode in the last year increased 52% 2005–2017 (from 8.7% to 13.2%) among adolescents aged 12 to 17 and 63% 2009 –2017 (from 8.1% to 13.2%) among young adults 18 –25. Serious psychological distress in the last month and suicide-related outcomes (suicidal ideation, plans, attempts, and deaths by suicide) in the last year also increased among young adults 18 –25 from 2008 –2017 (with a 71% increase in serious psychological distress), with less consistent and weaker increases among adults ages 26 and over. Hierarchical linear modeling analyses separating the effects of age, period, and birth cohort suggest the trends among adults are primarily due to cohort, with a steady rise in mood disorder and suicide-related outcomes between cohorts born from the early 1980s (Millennials) to the late 1990s (iGen). Cultural trends contributing to an increase in mood disorders and suicidal thoughts and behaviors since the mid-2000s, including the rise of electronic communication and digital media and declines in sleep duration, may have had a larger impact on younger people, creating a cohort effect.