Résumé : The detection of individuals at clinical ultra-high risk for psychosis (CHR-P) may be a key limiting step for early interventions, and there is some uncertainty regarding the true clinical reliability of the CHR-P states. The aim of this study was to explore how practitioners who were in the direct treatment of children with psychiatric disorders [child psychiatry specialists/trainees (n = 227, n = 131), adult psychiatrists (n = 27), and child neurologists (n = 2)] perceive the DSM-5-Attenuated Psychosis Syndrome (DSM-5-APS), and their clinical routine practice in the treatment of it. Three vignettes describing fictional cases presented with symptoms of either DSM-5-Schizophrenia, DSM-5-APS, and no psychotic symptoms were created. We asked these practitioners to apply a DSM-5 diagnosis and to choose appropriate treatment(s) for these vignettes. Of the responders, 43% correctly diagnosed the APS vignette, whereas 37.4% mentioned that it had a full-blown psychotic episode. Regarding the therapeutic approach for the APS vignette, 72.1% of all practitioners chose a psychopharmacological intervention and 32% individual psychotherapy. This study showed that the diagnostic inter-rater reliability of the DSM-5-APS among child/adolescent mental health practitioners was consistent with the results from the DSM-5 field trials (Kappa = 0.46). Moreover, almost three in four practitioners endorsed psychopharmacological intervention as a treatment option for the DSM-5-APS case. The lack of evidence of psychopharmacological interventions in CHR-P situations emphasizes that the least harmful interventions should be recommended. Thus, our findings indicated a need for raising awareness regarding the CHR-P paradigm and its treatment as well as the development of solid guidelines that can be implemented in clinical practice.