DIALOG: Understanding Disorganisation: A Language-focused Global Initiative in Psychosis

What this study is about

Disorganized speech, language and communication, also called 'formal thought disorder,' is a key part of severe mental illnesses like psychosis and mood disorders. When someone's communication is disorganized, it makes social interactions difficult, increases stigma and affect educational and employment opportunities. However, we do not know much about why this happens. This project, called DIALOG, aims to understand the brain's role in disorganization by studying everyday language use instead of traditional clinical ratings. The study will look at how our brain creates predictions during interactions and how these processes break down in psychosis. This international project also includes experts with personal experience of mental illness. The study will look at speech, thinking patterns, symptoms, and brain waves. The goal of the study is to see if brain waves are disrupted in psychosis, especially in language-related problems. Speech tasks, like describing pictures, talking about a significant event, and telling a story are administered. These tasks will be audio-recorded for analysis. Non-invasive brain imaging technologies such as Magnetoencephalography (MEG) and Magnetic Resonance Imaging (MRI) are utilized. MRI creates images of the brain's structure, while MEG records magnetic activity from neurons, shown as brain waves. The MRI machine uses a large magnet to create images, and MEG captures small magnetic field changes from brain activity. Participants will also undergo clinical and neurocognitive assessments. The study will combine Large Language Models (LLM) applied to speech recordings with large scale participant data from neuroimaging tools (MRI/MEG). The goal of DIALOG is to pioneer a computationally informed, molecular-to systems-level account of disorganisation, identifying the precise mechanisms that can be targeted with novel treatments. This project aims to gather speech and neuroimaging data from Montreal \[100 healthy volunteers and 50 patients with psychosis\], Groningen \[17 synaptic density PET scans\], Cardiff \[600 participants\] and Marburg \[1600 participants\] with schizophrenia, schizoaffective disorder or mood disorders and user acceptability data at Pavia and Melbourne.

Who can join (things the study team will check)

✅ You may be able to join if…

• English or French speaking participants, male or female; age 18-65 years. Patients who have been previously diagnosed by their treating physician based on the Diagnostic and Statistical Manual of Mental Disorders 5 Edition (DSM 5) criteria for schizophrenia or schizoaffective disorder. Ethnically and socioeconomically diverse individuals from urban catchments. Women are under-represented in psychosis studies but across sexes disorganisation is equally severe. We aim for >40% women in our samples via broader inclusion criteria not limited to schizophrenia. Healthy Controls group-matched with the patients for age (within 2 years), and sex matched to patient sample; and have no personal or first-degree family history of Severe Mental Disorders (SMD).

Where this trial is running

• Douglas Mental Health University Institute, Montreal, Quebec, Canada

Who to contact

Lena Palaniyappan, MD, PhD, FRCPC · 5147616131 · lena.palaniyappan@mcgill.ca

It's completely normal to call and ask questions before deciding anything. Mention the study ID: NCT06978465.