Does social media use show established neurocognitive signatures of addiction?

Social media platforms incorporate design features hypothesised to drive addiction through neurocognitive pathways. We tested three neurocognitive signatures of addiction (elevated wanting, wanting-liking dissociation, devaluation insensitivity) across two preregistered within-subjects experiments using an effort-based decision-making framework. Experiment 1 (N=95) compared motivated behaviour for TikTok and Netflix in a general population sample. Experiment 2 (N=235) compared motivated behaviour for regular and devalued TikTok rewards in individuals stratified by self-reported TikTok addiction. Across both experiments, wanting did not differ between conditions or groups. Although a wanting-liking dissociation was observed for TikTok, this was driven by reduced liking rather than elevated wanting, inverting the mechanistic prediction of the Incentive Sensitisation Theory. The dissociation was also unrelated to self-reported addiction severity. Devaluation insensitivity was not observed for individuals with self-reported addiction. The findings challenge conceptualisations of problematic social media use as neurobiologically analogous to established addictions.