Validity and reliability of the Polish Maladaptive Daydreaming Scale (PMDS-16) and its short form (PMDS-5).

Maladaptive daydreaming (MD) defines excessive use of fantasy, which replaces human interaction and/or interferes with academic, interpersonal, or vocational functioning. This study tests psychometric properties of the Polish version of the Maladaptive Daydreaming Scale (PMDS-16) and a short 5-item version derived from it (PMDS-5), and their capacity to screen for MD. The relationship between MD, resilience and the quality of life was also explored. Validity and reliability were examined in a sample of 491 participants in nonclinical (n = 315) and mixed-clinical (n = 176) groups who completed the tests online. The exploratory factor analysis with principal component analysis method of parameter estimation without rotation confirmed a one-factor solution of both instruments. Reliability of both versions was corroborated by Cronbach's alpha coefficient (PMDS-16: >.941; PMDS-5: >.931). The cutoff score maximizing sensitivity and specificity for MD was 42 in both instruments, but the short version had better discriminating properties. People who identified themselves as maladaptive daydreamers in comparison to those who did not had significantly higher scores in both instruments. Maladaptive daydreamers also had lower quality of life in the psychological and social relationships domains and poorer resilience. Both PMDS-16 and PMDS-5 proved to have satisfactory psychometric properties. They have similar psychometric properties, although PMDS-5 has better discriminating power and can be used effectively for the screening of MD.