For years, smartphones have been cast as the villains of modern life, blamed for rising rates of anxiety, depression, and distraction.
However, a new study analyzing over a quarter-million days of smartphone use across 10,099 American adults suggests the connection between phone habits and mental well-being may be far weaker than previously thought.
Published recently in Proceedings of the National Academy of Sciences (PNAS), the research represents one of the most extensive and detailed investigations ever on how real-world smartphone behavior relates to mood.
Using anonymized usage logs collected directly from participants’ Android devices, researchers tracked every unlock, app session, and screen minute over four weeks, then compared those patterns with daily mood ratings.
Their verdict: The data on mood and phone use don’t support the theory that smartphone use negatively affects mental health.
“Smartphones are an indispensable tool in everyday life; however, there are concerns about how their use may impact mental health and well-being,” researchers write. “Our analysis of a quarter of a million days of objective smartphone usage across over 10,000 diverse adult participants reveals little evidence for strong bidirectional associations between mental well-being and smartphone use.”
Researchers set out to test a deceptively simple but widely debated question: Do smartphones actually make people feel worse?
To answer that, they went far beyond traditional surveys, which often rely on participants estimating how much time they spend online, a notoriously unreliable measure. Previous studies have shown that self-reported phone use can overestimate reality by as much as 12 hours per week. Instead, researchers used objective data from Android system logs, offering a precise, minute-by-minute picture of how people actually used their phones.
Across the entire sample, participants spent a median of about 6 hours per day on their phones, unlocking them roughly 41 times daily. Of that, only about 43 minutes were spent on social media apps, with the rest going to messaging, navigation, productivity, and other “non-social” categories.
According to Pew Research, despite nearly 85% of Americans owning smartphones, and some users spending upwards of almost 25% of their day using them, researchers found no significant evidence that heavier phone use predicted lower mood, either within individuals or across the group as a whole. In fact, in some cases, people reported slightly better moods during weeks when they used non-social apps more than usual.
While the overall effects were small to nonexistent, subtle patterns were evident in the data. Younger adults showed a weak cross-sectional link between social media use and lower mood. However, this relationship disappeared when analyzed over time.
Similarly, women and “individuals identifying as genderqueer” tended to use social and non-social apps more frequently and reported lower average mood scores than men. However, again, demographic factors like age and gender were not stronger predictors of mood than smartphone use itself.
The authors argue that this finding underscores how misleading it can be to conflate correlation with causation. Even statistically significant effects in a massive dataset may have little practical impact.
In one example, the team calculated that for an average user to lower their mood score by just one point, they would need to spend an impossible 18 extra hours per day using non-social apps.
“This means the effects we observed are so small that they require implausibly large behavioral changes to produce even minor mood shifts,” researchers explain.
The new study also addresses a recurring problem in digital mental health research: the gap between perception and reality. Most past studies have relied on self-reports, which tend to exaggerate usage and obscure important nuances.
A person might say they spend “hours scrolling social media.” Still, that time could be split between messaging friends, reading the news, or watching videos. These activities may have very different emotional effects.
By using objective logs, researchers were able to distinguish between social media apps (like Facebook or Instagram) and non-social apps (such as Google Maps or Spotify).
Interestingly, they found that while high social app use wasn’t associated with worse mood, greater use of non-social apps correlated with slightly better moods within individuals, possibly reflecting productive or rewarding activities like planning, learning, or entertainment.
However, the researchers caution that these patterns don’t necessarily prove smartphones are beneficial. The results only demonstrate that their relationship with mental health is more intricate, contextual, and likely overstated in public discourse.
“Because our study revealed predominantly small or null effect sizes, and because the associations between non-social app usage and mood differed between between-subjects and within-subjects analyses, replication of these findings is crucial before drawing strong conclusions,” researchers write.
The findings arrive amid a wave of concern about social media’s impact on mental health in recent years. The U.S. Surgeon General issued a 2023 advisory warning that digital platforms may pose “a profound risk of harm to the mental health and well-being of children and adolescents.” In 2024, then-Surgeon General Dr. Vivek Murthy even called on Congress to require warning labels on social media apps.
While those warnings primarily target adolescent use, the broader narrative that more screen time equals worse well-being has largely dominated public perception.
However, the data from this adult-focused study challenge that narrative. The researchers emphasize that causation cannot be inferred from correlation, and that the direction of influence might even run the other way, with people turning to their phones when they already feel down. This finding is significant as it suggests that our mood might influence our phone use, rather than the other way around.
Indeed, the study found no evidence that mood in one week predicted smartphone use the next, suggesting that feeling worse doesn’t lead to more scrolling, either.
“Despite the sometimes vociferous discourse surrounding smartphone and social media use, mental health, and well-being, our results show little evidence of short-term impact of smartphone use on mood (a key indicator of mental well-being) from week to week or of mood on smartphone use over the same timescale,” researchers write. “Moreover, among the findings that were statistically significant, we observed a mix of associations with both negative and positive mood outcomes.”
Researchers propose a more nuanced framework for treating smartphones not as inherently harmful but as contexts for experience. Within that context, a wide range of behaviors — from social connection to passive consumption — can shape well-being in very different ways.
In other words, it’s not how much you use your phone, but how you use it.
That distinction matters for mental health researchers, app designers, and policymakers alike. While blanket restrictions or screen-time caps might sound appealing, evidence suggests they’re unlikely to improve well-being.
“Our findings are largely consistent with other published reports of negligible (i.e., very small effect sizes) and/or nonsignificant relationships between objective smartphone usage patterns and well-being measures,” researchers conclude.
“It is probably best to think of smartphones as a context in which a wide variety of experiences occur, and as such, further research should focus on the factors that increase or reduce the likelihood of beneficial versus harmful online experiences, rather than the use of smartphones or particular categories of applications,” the authors write.
Tim McMillan is a retired law enforcement executive, investigative reporter and co-founder of The Debrief. His writing typically focuses on defense, national security, the Intelligence Community and topics related to psychology. You can follow Tim on Twitter: @LtTimMcMillan. Tim can be reached by email: tim@thedebrief.org or through encrypted email: LtTimMcMillan@protonmail.com