Gen Z is reporting a sharp decline in life satisfaction compared with Millennials at the same age. Fewer than half now say they are “thriving,” compared with nearly two-thirds of young adults in the early 2010s.

Gallup’s latest Life Evaluation Index also found that 27% of adults between 18 and 29 are receiving treatment for depression — an increase of 11 percentage points since 2019.

Many young adults said they feel increasingly disconnected from friends and romantic partners and are experiencing less happiness. Fewer than one in three reported accomplishing most of their goals over the previous year.

“Gen Z has had constant access to their smartphones and social media, along with a global pandemic and financial pressures, including housing costs, that no previous generation has faced in quite the same way,” Dr. Katrina Furey, a Connecticut-based psychiatrist, told The Post.

She said the isolation young people experienced during the COVID-19 pandemic, particularly during crucial developmental years, appears to have had a lasting effect.

“Depression and loneliness can really tie into your social connections,” Furey said.

She added that many members of Gen Z are expressing deep anxiety about what lies ahead.

The survey found that just 44% of young adults consider themselves to be “thriving,” compared with 64% of people in the same age range in 2010.

Most of the deterioration in young adults’ outlook has occurred since 2019, with the steepest setback arriving during the pandemic, according to the polling data.

The share of young adults who said they were thriving slipped steadily throughout the 2010s, falling from 64% to 57% by 2019. In 2020, it plunged to 39%.

CHECK THIS OUT: Elon Musk Calls Waymo Robotaxis ‘Pet Destroyers’

Although the figure recovered somewhat, reaching just above 50% in 2023, it has since declined again.

Young adults also recorded declines across every major measure of well-being. Only 47% said their relationship with a spouse, partner or closest friend was stronger than ever, down from 65% in 2019.

Just 64% of Gen Z respondents said they had experienced joy the previous day, 17 percentage points lower than young adults reported in 2019. Only 28% said they had felt active and productive every day during the past week, a 16-point drop.

“They are also the first generation that has really grown up online,” said Furey, founder of Repro Psych Academy. Research has connected social media use with higher rates of eating disorders and depression, she noted, adding that it is difficult to separate those trends from Gen Z’s declining well-being.

Only one-third of Gen Z respondents said they had a leader or role model in their lives who inspired enthusiasm about the future. That compares with 47% of young adults who said the same in 2019.

Just 41% said they were satisfied with their standard of living compared with the people around them, down 14 percentage points from 2019.

Meanwhile, only 31% said they had achieved most of their goals in the past 12 months, compared with 44% previously.

Gen Z reported the lowest levels of optimism, but the broader picture suggests that dissatisfaction is not limited to the youngest generation.

Millennials have experienced a comparable slide, with only 45% of adults ages 30 to 44 describing themselves as thriving.

Gen X has seen a smaller decline than younger adults, but only 46% of people ages 45 to 64 now say they are thriving — matching the generation’s previous low, recorded in 2008 during the Great Recession.

The only generation that has higher life evaluations now than in 2008 is Baby Boomers, with the percentage of those aged 65 and older who are “thriving” rising steadily from 38% in 2008 to 53% in 2026, matching their record high of 2021.