Table 1.

A list of included studies for associations between FTD and functioning outcomes

First author	Publication year	Published journal	Study groups	Sample size	Mean age	FTD measures	Outcome measures	Main findings and conclusion
Harrow, M	1986	Schizophrenia Bulletin	SCZ, other psychotic patients, and non-psychotic patients	191	23	Bizarre-idiosyncratic thinking	Occupational functioning, subsequent unemployment, relapse/re-hospitalisation rates (LKPS and SCS)	Subsequent unemployment and higher relapse/re-hospitalisation rates in schizophrenia patients experiencing enduring FTD
Marengo, JT	1987	Arch Gen Psychiatry	SCZ, other psychotic, and non-psychotic patients	191	23	Bizarre-idiosyncratic thinking	Occupational functioning, subsequent unemployment, relapse/re-hospitalisation rates (LKPS and SCS)	Patients with enduring thought disorder signs proved to be a poor-outcome group
Racenstein, JM	1999	J Nerv Ment Dis	SCZ, other psychotic, and non-psychotic patients	191	23	Bizarre-idiosyncratic thinking	Occupational functioning, subsequent unemployment, relapse/re-hospitalisation rates (LKPS and SCS)	FTD and functioning correlated in the first eight-year of schizophrenia. A stronger correlation between FTD and occupational than social functioning
Kotov, R	2016	Journal of Abnormal Psychology	First-admission inpatients with psychosis	628	30	SAPS and SANS	GAF, QLS (Social and role functioning), residential independency	A four-factors model (reality distortion, disorganization, inexpressivity, and apathy/asociality) having a stable and replicable validity in predicting outcomes
Minor, KS	2016	J Abnorm Psychol	Early stages of psychosis	38	24.89	CDI	GFS and GFR	Positive FTD and affective reactivity were consistently accounting for poor social functioning and associated with poor role functioning in some cases in EP
Roche, E	2016	Schizophrenia Research	FEP	680	33.42	Disorganization, verbosity, poverty of speech	Social and occupational functioning (MIRECC GAF subscales), number of hospitalisations	Higher baseline severity of disorganization predicted a greater number of hospitalisations and prolonged hospitalisation during the first year of illness
Burton, CZ	2019	Schizophrenia Research	CLR, CHR, EFEP	327	16.69	SIPS	GFS and GFR	Baseline negative symptoms and thought disorder appeared to predict the functional outcome for up to 2 years among adolescents and young adults at risk for psychosis
Bearden, CE	2011	Journal of the American Academy of Child and Adolescent Psychiatry	CHR	105	16.66	Illogical thinking, poverty of content (POC), and referential cohesion	GFS and GFR	Transited to psychosis, predicted significantly social and role functioning at follow-up

FTD formal thought disorder, CDI communication disturbances index, FEP first episode psychosis, EP early psychosis, CLR clinical low risk, CHR clinical high risk, UHR ultra-high risk, HR high risk, LR low risk, ARMS at-risk mental state, APS attenuated psychosis syndrome, APSS attenuated positive symptom syndrome, LKPS levenstein, klein, and pollack scale, SCS strauss and carpenter scale, OPCRIT operational criteria for psychotic illness tool, SAPS scale for the assessment of positive symptoms, SANS scale for the assessment of negative symptoms, CAARMS comprehensive assessment of at-risk mental states, SIPS structured interview for prodromal syndromes, SCZ schizophrenia, SOPS scale of prodromal symptoms, WERCAP Washington early recognition center affectivity and psychosis screen, GAF global assessment of functioning, GFS global functioning scale-social GFR global functioning scale-role, QLS quality of life scale