Researchers said a fifth of young participants admitted their online profile bears little resemblance to reality, and that their recollection of past events has been distorted by their own fabrications.
In a poll, young adults, aged between 18 and 24, said they frequently lie about their relationships, promotions at work and holidays, The Telegraph reported.
According to psychologist Dr Richard Sherry, a founding member of the Society for Neuropsychoanalysis, social media has the power to "undermine the coherence between our real, lived lives and memories."
The study was commissioned by online journal repository Pencourage.