Brain Imaging of Cognition Inn Schizophrenia and Depression

This study uses Functional Magnetic Resonance Imaging (fMRI) which is a technique that takes a 3D picture of the brain using magnetic fields. It allows researchers to estimate how active different regions of the brain are. The aim of this study is to use fMRI to better understand the cognitive problems that individuals living with schizophrenia, schizoaffective disorder, or depression experience.

The study will involve three visits at The Royal's Institute of Mental Health Research in Ottawa, Canada. Each visit will last about 2.5 hours long.

Visits 1 and 2: Participants are asked to fill out several questionnaires on a computer. Participants are also asked to answer some questions about their current and past mental health as well as perform some tasks involving general thinking skills.

Visit 3: Participants will complete a brain scan using fMRI. Throughout the experiment, participants will perform three short tasks in the fMRI scanner. Participants will use buttons to answer some questions in response to some words and pictures.

Inclusion criteria

• age 18-60 years
• current Intelligence Quotient (IQ) > 70 as measured by the Wechsler Abbreviated Scale of Intelligence (WASI)
• the ability to read and speak fluent English
• a diagnosis of schizophrenia, schizoaffective or major depression disorder
• stable medication for more than one month

Exclusion criteria

• significant neurological or other medical disorders that may produce cognitive impairment
• a recent history of substance abuse or dependence (within the past 3 months)
• any magnetic resonance imaging (MRI) contraindications (e.g. metallic head implant, history of seizure, pacemaker)
• decisional incapacity requiring a guardian
• taking medications that are rated as Anticholinergic Burden (ACB) Score 3 (severe) or taking benzodiazepines on a daily basis
• Finally, participants could not be severely symptomatic at the time of study enrolment to ensure that they could understand and complete all study assessments. This criterion was defined as a score ≤34 on the Montgomery-Åsberg Depression Rating Scale (MADRS; Montgomery & Åsberg, 1979) for the MDD group and a score ≤95 on the Positive and Negative Syndrome Scale (PANSS; Kay et al., 1987) for the SZ group.