Formal thought disorder in people at ultra-high risk of psychosis

Arsime Demjaha; Sara Weinstein; Daniel Stahl; Fern Day; Lucia Valmaggia; Grazia Rutigliano; Andrea De Micheli; Paolo Fusar-Poli; Philip McGuire

doi:10.1192/bjpo.bp.116.004408

Formal thought disorder in people at ultra-high risk of psychosis

BJPsych Open. 2017 Jul 14;3(4):165-170. doi: 10.1192/bjpo.bp.116.004408. eCollection 2017 Jul.

Authors

Arsime Demjaha¹, Sara Weinstein², Daniel Stahl³, Fern Day¹, Lucia Valmaggia¹, Grazia Rutigliano⁴, Andrea De Micheli⁵, Paolo Fusar-Poli¹, Philip McGuire¹

Affiliations

¹ , PhD, Department of Psychosis Studies, Biomedical Research Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, UK.
² , PhD, Boeing Vancouver Labs, Vancuver, British Columbia, Canada.
³ , PhD, Department of Biostatistics, Institute of Psychiatry, Psychology and Neuroscience, King's College London, UK.
⁴ , MD, Department of Psychosis Studies, Biomedical Research Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, UK, and Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy.
⁵ , MD, Department of Psychosis Studies, Biomedical Research Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, UK, and Department of Brain and Behavioural Sciences, University of Pavia, Pavia, Italy.

Abstract

Background: Formal thought disorder is a cardinal feature of psychosis. However, the extent to which formal thought disorder is evident in ultra-high-risk individuals and whether it is linked to the progression to psychosis remains unclear.

Aims: Examine the severity of formal thought disorder in ultra-high-risk participants and its association with future psychosis.

Method: The Thought and Language Index (TLI) was used to assess 24 ultra-high-risk participants, 16 people with first-episode psychosis and 13 healthy controls. Ultra-high-risk individuals were followed up for a mean duration of 7 years (s.d.=1.5) to determine the relationship between formal thought disorder at baseline and transition to psychosis.

Results: TLI scores were significantly greater in the ultra-high-risk group compared with the healthy control group (effect size (ES)=1.2), but lower than in people with first-episode psychosis (ES=0.8). Total and negative TLI scores were higher in ultra-high-risk individuals who developed psychosis, but this was not significant. Combining negative TLI scores with attenuated psychotic symptoms and basic symptoms predicted transition to psychosis (P=0.04; ES=1.04).

Conclusions: TLI is beneficial in evaluating formal thought disorder in ultra-high-risk participants, and complements existing instruments for the evaluation of psychopathology in this group.

Declaration of interests: None.

Copyright and usage: © The Royal College of Psychiatrists 2017. This is an open access article distributed under the terms of the Creative Commons Non-Commercial, No Derivatives (CC BY-NC-ND) license.