Supplementary file 1_Platform-specific digital media use and psychological distress among Turkish adults: evidence from a nationally representative, cross-sectional survey.docx

Instagram use (β = +.066, p = .011) was associated with higher psychological distress and WhatsApp use (β = -.073, p = .007) with lower distress, whereas total internet time, TikTok, and YouTube showed no detectable association. Overall social-media time was likewise positively associated with distress (β = +.088, p = .016), but the platform contrasts, not aggregate exposure, survived the most demanding clustering and exposure-scale checks.

The positive Instagram association declined with age and was statistically indistinguishable from zero by the early forties, a secondary finding that turned on whether loneliness entered the model (age-by-Instagram β = -.069, p = .014 with loneliness, β = -.060, p = .059 without). Adding loneliness — an affective covariate overlapping the outcome battery — raised explained variance to R² = .359 (largely shared variance) while the platform and aggregate coefficients remained significant.

In this national sample the platform types diverged: algorithm-driven image-platform use (Instagram) showed a small positive association with distress, interpersonal-messaging use (WhatsApp) a small inverse (protective-direction) one. The headline effect sizes were below Cohen’s small-effect benchmark and estimated at the limit of what this design could detect, and the cross-sectional data require longitudinal confirmation of the platform contrasts.

Whether distinguishing platform types, rather than treating screen time as uniform, improves population-level digital well-being efforts remains a hypothesis for longitudinal and experimental testing.</p>