The honest answer is: it depends heavily on the person, platform, and pattern of use. Here's a balanced breakdown.
Where the harm shows up
•Teen mental health correlations are concerning, especially for adolescent girls—rates of anxiety and depression rose alongside heavy social media adoption, though researchers still debate how much is causal versus correlated with other factors.
•Social comparison and highlight-reel culture can distort self-image and life satisfaction.
•Algorithmic design optimizes for engagement, not wellbeing—outrage and anxiety often "perform" well, which shapes what people see.
•It can fragment attention and displace sleep, exercise, or in-person interaction if unchecked.
•Misinformation spreads fast and can be hard to correct.
Where it genuinely helps
•People who are isolated—due to disability, geography, marginalized identity, or niche interests—often find real community and support they couldn't access otherwise.
•It's been useful for organizing (mutual aid, activism, small business, disaster response).
•For many adults, it's a low-stakes way to stay loosely connected with extended networks.
•Creative and economic opportunities exist for artists, writers, and entrepreneurs that didn't before.
What the research actually suggests
The effect size for most users is smaller than the discourse implies. Heavy, passive use (endless scrolling, comparison-driven) tends to correlate with worse outcomes. Active use (messaging friends, engaging with specific communities) tends to be neutral or positive. Age matters too—adolescents seem more vulnerable than adults.
So rather than "harmful" or "helpful" as a fixed property, it's more accurate to say the design (algorithmic feeds vs. chronological, engagement-optimization vs. user control) and the usage pattern (passive scrolling vs. active connection) determine which way it tilts for a given person.
What's prompting the question—are you thinking about this for yourself, a kid, or more of a policy/societal angle? That would help me get more specific.