Development and validation of the Symptomatic Transdiagnostic Test (S2T)

The categorical approach in psychiatry has received many criticisms. Modern research tends to develop a transdiagnostic approach. However, transdiagnostic works lack an overall understanding and focus mainly on anxiety and depression. The aim of the present study was to develop an easy to use tool to evaluate multiple dimensions opening the way for further research in the transdiagnostic approach. This will allow researchers to quickly assess the efficacy of psychotherapeutic interventions on multiple psychopathological dimensions.

First, we identified the main symptoms of psychopathology in a sample of mental healthcare workers. Second, we developed the Symptomatic Transdiagnostic Test (S2T) to assess the main symptoms of psychopathology. Third, we evaluated its psychometric properties (exploratory and confirmatory factor analysis, internal consistency) in three non-clinical samples and one clinical sample.

The 66-item S2T included eleven factors referring to: i) negative thoughts and mood; ii) psycho-traumatic and maladaptive symptoms; iii) addiction symptoms; iv) disturbed eating behavior; v) disturbed perception and behavior; vi) panic and agoraphobia; vii) emotional lability; viii) dejection; ix) neurodevelopmental manifestations; x) anxiety and xi) psychic hyperactivity. We found a high internal consistency for the general scale (α=0.96) and the subscales. We found a good concurrent validity. As expected, we found higher levels of symptoms within the clinical population as compared to the non-clinical samples, except for addiction symptoms and disrupted eating behavior. We found negative associations between the symptomatic dimensions and psychological skills.

The S2T is a relevant tool for clinicians and researchers to assess the psychopathological profile. The main psychopathological symptoms are negatively related to the psychological skills.