Among the mediation hypotheses, Facebook use frequency did notaccount for relations between psychopathology variables and PFU severity,rejecting H5. Habitual Facebook use can grow into problematicuse (Ryan et al., 2014; Salehan & Negahban, 2013), and psychopathologymay fuel this process based on I-PACE and DSMM. Perhapsour measurement of Facebook use frequency was not sensitive enoughor objectively measured to reveal such a finding.