The progression of disorder-specific brain pattern expression in schizophrenia over 9 years

• Published in: npj Schizophrenia
• Main Authors: Lieslehto, Johannes, Jääskeläinen, Erika, Kiviniemi, Vesa, Haapea, Marianne, Jones, Peter B., Murray, Graham K., Veijola, Juha, Dannlowski, Udo, Grotegerd, Dominik, Meinert, Susanne, Hahn, Tim, Ruef, Anne, Isohanni, Matti, Falkai, Peter, Miettunen, Jouko, Dwyer, Dominic B., Koutsouleris, Nikolaos
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2021
• Subjects: Northern Finland
• Online Access: https://kclpure.kcl.ac.uk/portal/en/publications/e01c122c-6fd7-4b76-8db3-1b39ee3ce53e; https://doi.org/10.1038/s41537-021-00157-0; http://www.scopus.com/inward/record.url?scp=85107929698&partnerID=8YFLogxK

Age plays a crucial role in the performance of schizophrenia vs. controls (SZ-HC) neuroimaging-based machine learning (ML) models as the accuracy of identifying first-episode psychosis from controls is poor compared to chronic patients. Resolving whether this finding reflects longitudinal progression in a disorder-specific brain pattern or a systematic but non-disorder-specific deviation from a normal brain aging (BA) trajectory in schizophrenia would help the clinical translation of diagnostic ML models. We trained two ML models on structural MRI data: an SZ-HC model based on 70 schizophrenia patients and 74 controls and a BA model (based on 561 healthy individuals, age range = 66 years). We then investigated the two models’ predictions in the naturalistic longitudinal Northern Finland Birth Cohort 1966 (NFBC1966) following 29 schizophrenia and 61 controls for nine years. The SZ-HC model’s schizophrenia-specificity was further assessed by utilizing independent validation (62 schizophrenia, 95 controls) and depression samples (203 depression, 203 controls). We found better performance at the NFBC1966 follow-up (sensitivity = 75.9%, specificity = 83.6%) compared to the baseline (sensitivity = 58.6%, specificity = 86.9%). This finding resulted from progression in disorder-specific pattern expression in schizophrenia and was not explained by concomitant acceleration of brain aging. The disorder-specific pattern’s progression reflected longitudinal changes in cognition, outcomes, and local brain changes, while BA captured treatment-related and global brain alterations. The SZ-HC model was also generalizable to independent schizophrenia validation samples but classified depression as control subjects. Our research underlines the importance of taking account of longitudinal progression in a disorder-specific pattern in schizophrenia when developing ML classifiers for different age groups.