Early Intervention Research and Clinical

We are deeply involved in Canadian and international service design and development. At the Douglas and McGill, we lead a joint clinical-research team at PEPP-Montreal, a widely recognized specialized early intervention service for psychosis with multicomponent patient-centered care. This has included examinations of the effects of outreach campaigns, the initial presentation and evolution of symptoms such as delusions and hallucinations but longitudinally and across successive cohorts, and the lessons these findings have for care provided during the early intervention window. More recently, we are pioneering the development of a transdiagnostic service for youth at-risk of severe mental illness.

Early Intervention Research and Clinical Care

Key Projects:

PEPP-Montreal has contributed to early psychosis becoming a Québec ministry priority, with all citizens having access to best-practice specialist care. It has seeded other early psychosis services in Quebec, Canada and globally and supported research and implementation efforts worldwide through international collaborations.

Zavaglia E, Joober R, Iyer SN, MacDonald K, Lepage M, Abadi S, Shah J, Ferrari M (2025). Implementation of a digital measurement-based care approach in an early intervention service for psychosis: the PEPP-Montreal electronic data capture protocol and its alignment with learning health system principles. Schizophrenia Research, 282, 141-149.
Percie du Sert O, Unrau J, Dama M, Palaniyappan L, Shah J, Joober R, Raucher-Chéné D, Malla A, Lepage M (2025). Latent trajectories of positive, negative symptoms and functioning in early intervention services for first episode psychosis: A 2-year follow-up study. Schizophrenia Bulletin, doi: 10.1093/schbul/sbaf045
Berisha F, Paquin V, Gold I, Misic B, Palaniyappan L, Malla A, Iyer S, Joober R, Lepage M, Shah JL (2025). Exploring delusional themes and other symptoms in first episode psychosis: A network analysis over two timepoints. Psychiatry Research, 344, 116349. doi:10.1016/j.psychres.2024.116349
Liu Y, Jalali S, Joober R, Lepage M, Iyer S, Shah J, Benrimoh D (2025). Subtyping first-episode psychosis based on longitudinal symptom trajectories using machine learning. NPJ Mental Health Research, 4(1), 18.
Mourgues-Codern C, Benrimoh D, Gandhi J, Farina EA, Vin R, Zamorano T, Parekh D, Malla A, Joober R, Lepage M, Iyer SN, Addington J, Bearden CE, Cadenhead KS, Cornblatt B, Keshavan M, Stone WS, Mathalon DH, Perkins DO, Walker EF, Cannon T, Woods S, Shah JL, Powers AR (2025). Emergence and dynamics of delusions and hallucinations across stages in early psychosis. Biological Psychiatry, S0006-3223(25)00990-4.
Aversa S, Ghanem J, Grunfeld G, Lemonde AC, Malla A, Iyer S, Joober R, Lepage M, Shah JL. (2024). Sociodemographic and clinical correlates of hallucinations in patients entering an early intervention program for first episode psychosis. Schizophrenia Research, 269, 86-92.
Grunfeld G, Lemonde AC, Paquin V, Gold I, Iyer S, Lepage M, Joober R, Malla A, Shah JL. (2024). Concordance of delusional themes across first and subsequent episodes of psychosis: Do they persist or change? JAMA Psychiatry. In press.
Aversa, S, Ghanem, J, Grunfeld, G, Lemonde, A C, Malla, A, Iyer, S, Joober, R, Lepage, M, Shah, JL. (2024). Sociodemographic and clinical correlates of hallucinations in patients entering an early intervention program for first episode psychosis. Schizophrenia Research, 269, 86-92.
Lemonde AC, Iyer SN, Malla A, Rangaswamy T, Ramachandran P, Mohan G, Gariepy G, Joober R, Taksal A, Boksa P, Shah JL (2023). Differential trajectories of delusional content and severity over two years of early intervention for psychosis: Comparison between Chennai, India and Montreal, Canada. Schizophrenia Bulletin, in press.
Grunfeld G, Lemonde A-C, Gold I, Iyer S, Joober R, Malla A, Boksa P, Shah JL (2022). “The more things change…?” Stability of delusional themes across 12 years of presentations to an early intervention service for psychosis. Social Psychiatry & Psychiatric Epidemiology, in press:
Fleming LM, Lemonde A-C, Benrimoh D, Gold JM, Taylor JR, Malla A, Joober R, Iyer SN, Lepage M, Shah JL, Corlett PR (2023). Using dimensionality-reduction to understand the organization of psychotic symptoms in first episode and persistent psychotic illness. Scientific Reports, 13(1), 4841.
Lemonde A-C, Joober R, Malla A, Iyer S, Lepage M, Boksa P*, Shah JL* (2020). Delusional content at initial presentation to a catchment-based early intervention service for psychosis. British Journal of Psychiatry, 218(4), 217-223.
Pruessner M, Faridi K, Shah J, Rabinovitch M, Iyer SN, Abadi S, Pawliuk N, Joober R, Malla A (2016). The Clinic for Assessment of Youth At Risk (CAYR): 10 years of service delivery and research targeting the prevention of psychosis in Montréal, Canada. Early Intervention in Psychiatry, 11(2), 177-184.

With funding from the Zhubin Foundation and Rossy Foundation, we are in the midst of developing and evaluating a novel service for youth at risk for severe mental illnesses.

Jordan G, Bassetto S, DeLuca J, Dobbs MF, Florence A, Allemang B, O’Keeffe D, Basile M, Funaro MC, Davidson L, Ben-David S, Shah J (2024). Personal recovery among people at risk for developing serious mental health problems: A qualitative systematic review. Psychiatric Services, in press.
Bonnett LJ, Hunt A, Flores A, Tudur Smith C, Varese F, Byrne R, Law H, Milicevic M, Carney R, Parker S, Yung AR, IPPACT Study Group (2025). Clinical prediction model for transition to psychosis in individuals meeting at risk mental state criteria. Schizophrenia, 11(1), 29. doi:10.1038/s41537-025-00582-5
Jordan G, Kinkaid M, Iyer SN, Joober R, Goldberg K, Malla A, Shah JL (2018). Baby or bathwater? Referrals of “non-cases” in a targeted early identification intervention for psychosis. Social Psychiatry & Psychiatric Epidemiology, 53(7), 757-761.
Shah JL (2015). Sub-threshold mental illness in adolescents: Within and beyond DSM’s boundaries. Social Psychiatry & Psychiatric Epidemiology, 50(5), 675-677.