The possible role of altered oropharyngeal microbiota in differentiating true psychosis from malingered psychosis in a forensic psychiatric setting

•It is sometimes challenging to differentiate between true and malingered psychosis.•Identifying reliable and innovative diagnostic alternatives seems crucial.•The saliva microbiome and periodontal disease were potentially associated with true psychosis.•Future research can take advantage of oropharyngeal microbiota composition to recognize true psychosis. Over the past few years, malingered psychosis has had a progressive occurrence since a great deal of attention has been directed to the closures of long-stay psychiatric institutions and care in the community. Therefore, malingered psychosis needs to be identified to conduct precise forensic assessments and prevent miscarriages of justice and misuse of restricted healthcare resources. Although, over the past decades, some practical psychometric and strategic tools have been introduced to diagnose true psychosis, it is still sometimes challenging to differentiate between true and malingered psychosis. Hence, identifying reliable and innovative diagnostic alternatives seems crucial. In this respect, some preliminary results revealed the saliva microbiome and periodontal disease were potentially associated with true psychosis. Therefore, since oropharyngeal microbial compositions are highly different among healthy controls and patients with true psychosis, we hypothesized that future research can take advantage of oropharyngeal microbiota composition to differentiate between true and fake psychosis during the early stages of forensic psychiatric evaluation. As a substrate of interest, oropharyngeal secretion samples could also be used for characterizing the various stages of psychosis in a forensic psychiatric setting.