In the context of first-episode psychosis, an organic or toxic etiology is identified in approximately 14 % of cases. However, biomarkers of primary psychosis are lacking, and there are no well-established red flags for identifying individuals presenting with secondary psychosis. Given that early diagnosis significantly impacts prognosis, this article proposes a standardized, multidisciplinary approach to managing first-episode psychosis, aimed at increasing the sensitivity for detecting secondary psychoses. Our protocol, based on current evidence, can be implemented in both emergency and outpatient settings. It enables urgent referral to a specialist, most frequently a neurologist, based on the presence of biological alterations and clinical red flags.