Sweden’s Futura01 cohort has followed a national sample of adolescents who were in ninth grade in 2016 and 2017 into early adulthood, collecting detailed survey data alongside linked national registry records. A 2025 paper drawing on this cohort, published in the Scandinavian Journal of Public Health by Sara Brolin Låftman, Andreas Lundin, and Viveca Östberg, asked a specific question: does the social support a person perceives from family, from friends, and from a romantic partner at age 17 to 18 predict fewer symptoms of depression and anxiety a few years later, at age 20 to 21?
The study, based on 2,722 participants, found a more specific and more limited pattern than the broad claim that friendship protects mental health during hard times. When the researchers accounted for all three sources of support at once, family support in late adolescence predicted lower symptoms of both depression and anxiety years later. Support from friends predicted lower anxiety symptoms specifically, but showed no significant independent association with depression once family support was accounted for.
This is one longitudinal cohort study, not a definitive ranking of which relationship matters most in every circumstance, and it measured a specific age transition, late adolescence into early adulthood, rather than adult friendship broadly. But it is a real, prospective dataset following the same people over several years, which makes it considerably more informative than a cross-sectional survey asking people how supported they feel at a single moment.
Why the distinction between depression and anxiety matters here
The finding is easy to flatten into “family matters more than friends,” but the more precise reading is narrower and more interesting: perceived friend support seems to do something specific rather than something general. It tracked with lower anxiety symptoms specifically, not with the full range of mental health difficulties this age group faces. Family support, by contrast, showed a broader protective association covering both depression and anxiety symptoms.
One plausible reason, consistent with the broader literature on social support that this study builds on, is that different relationships tend to supply different kinds of support. Sheldon Cohen and Thomas Wills, in an influential and much-cited 1985 review in Psychological Bulletin, distinguished between several functions of support, including emotional reassurance, practical help, and the kind of steady, unconditional backing that does not depend on a specific crisis. Friendship, particularly among people still establishing their adult lives, may supply more of the situational reassurance that eases anxiety about a specific worry, while family relationships, often longer-standing and less contingent on a shared life stage, may supply the steadier baseline connected to lower depression risk over time.
What this means for “friendships keep you sane”
None of this means friendship is a weak or unimportant source of support. The Futura01 finding is a genuine, positive, prospective result: perceived friend support at 17 to 18 predicted measurably lower anxiety symptoms years later, even after the researchers statistically accounted for family and romantic support at the same time. What the data does not support is the broader, flatter version of the claim that friendship is the primary thing keeping a person’s mental health intact through a difficult period in general. The protective role researchers actually measured was more specific: friendship mattered for anxiety, not for the full breadth of the mental health difficulties young adults report.
What it might mean in practice
If the pattern this study found holds beyond the specific age group it examined, it suggests a more useful way to think about which relationship to lean on during a hard stretch than simply “spend more time with friends” or “call your family more.” A specific, anxious worry, an upcoming decision, a source of acute stress that keeps circling in someone’s mind, may be exactly the kind of difficulty where friend support does the most measurable good, based on what this dataset actually found. A longer, heavier low mood, the kind more associated with depression, showed its stronger statistical link to family support in this same sample. That is a more specific and more actionable distinction than treating all social contact as interchangeable protection against a difficult period.
What this does not settle
The Futura01 sample covers a specific developmental window, adolescence transitioning into early adulthood, in one country, and the pattern may look different at other ages or in populations facing different kinds of hardship, such as bereavement, job loss, or chronic illness, none of which this study specifically measured. The researchers also relied on perceived support, how supported participants felt they had, rather than a count of actual friends or contact frequency, which is a meaningfully different measure than simply having more friendships. What the study does offer, read honestly, is a more precise account than the popular version: friendship in this dataset was linked to one specific, real benefit, lower anxiety, rather than serving as a broad, all-purpose buffer against every form of difficulty a hard period can bring.