2.2.4. Mobile phone addiction index Scale-17 (MPAI-17)

The MPAI-17 scale was developed by Leung and Louis to identify symptoms of cell phone addiction and serve as a comprehensive assessment of cell phone addiction [36], extending the research of Bianchi and Phillips and meeting the assumptions of the Diagnostic and Statistical Manual of Mental Disorders for substance addiction symptoms [37]. Participants answered items on a 5-point rating scale (1 = not at all, 2 = rarely, 3 = occasionally, 4 = often, and 5 = always); a higher average score indicated more severe addiction, which has been widely used in the measurement of SPD [7,38]. The Cronbach alpha coefficients were 0.945 for Study 1 and 0.936 for Study 2, respectively.