Current State of Application of Formal Thought Disorder Screening Methods in First-Degree Relatives of Patients With Schizophrenia: A Narrative Review

Historically, formal thought disorder (FTD) has been considered one of the distinctive key symptoms of schizophrenia and is still regarded as an important early warning sign and a marker of illness severity with solid predictive value. Recent studies found that the presence of FTD is predictive of the subsequent diagnosis of schizophrenia and often precedes the frank clinical picture by several months. Much effort has been put into developing scales that can reliably detect FTD and can be readily applied in routine clinical practice. This narrative review investigated the use of FTD as a screening tool to assess risk in first-degree relatives of patients with schizophrenia. The results show that the use of these scales in first-degree relatives of schizophrenic individuals during clinical contact and counseling is still an exception, despite their uniquely heightened vulnerability profile. To our knowledge, this is the first time that the application of FTD screening methods in first-degree relatives of schizophrenic individuals has been reviewed in a structured way.