Submitted for Publication: February 18, 2015; final revision received and accepted April 21, 2015.
Published Online: July 1, 2015. doi:10.1001/jamapsychiatry.2015.0891.
Study concept and design: Graff-Guerrero, Rajji, Mulsant, Uchida, Gerretsen, Pollock, Mamo.
Acquisition, analysis, or interpretation of data: Graff-Guerrero, Rajji, Mulsant, Nakajima, Caravaggio, Suzuki, Uchida, Gerretsen, Mar, Mamo.
Drafting of the manuscript: Graff-Guerrero, Rajji, Nakajima, Mar.
Critical revision of the manuscript for important intellectual content: Graff-Guerrero, Rajji, Mulsant, Nakajima, Caravaggio, Suzuki, Uchida, Gerretsen, Pollock, Mamo.
Statistical analysis: Graff-Guerrero, Rajji, Nakajima, Caravaggio, Uchida.
Obtained funding: Graff-Guerrero, Mulsant, Pollock, Mamo.
Administrative, technical, or material support: Graff-Guerrero, Nakajima, Suzuki, Uchida, Gerretsen, Mar, Pollock, Mamo.
Study supervision: Graff-Guerrero, Rajji, Mulsant, Suzuki, Mamo.
Conflict of Interest Disclosures: Dr Graff-Guerrero has received research support from the Canadian Institutes of Health Research (CIHR), US National Institutes of Health (NIH), Ontario Mental Health Foundation (OMHF), Brain and Behavior Research Foundation, Mexico Instituto de Ciencia y Tecnologia del Distrito Federal and Consejo Nacional de Ciencia y Tecnologia, and W. Garfield Weston Foundation. Dr Mulsant currently receives research funding from Brain Canada, the Centre for Addiction and Mental Health (CAMH) Foundation, the CIHR, and the US NIH. During the past 5 years, he received research support from Bristol-Myers Squibb, Eli-Lilly and Company, and Pfizer (all for medications used in NIH-funded clinical trials). He directly own stocks of General Electric (<$5000). Dr Nakajima has received fellowship grants from the CIHR, Japan Society for the Promotion of Science, and Nakatomi Foundation and manuscript fees from Dainippon-Sumitomo Pharma and Kyowa Hakko Kirin. Dr Suzuki has received speaker or manuscript fees from Astellas Pharmaceutical, Dainippon-Sumitomo Pharma, Eli Lilly and Company, Elsevier Japan, Janssen Pharmaceutical, Otsuka Pharma, and Weily Japan. Dr Uchida has received grants from Astellas Pharmaceutical, Eisai, Otsuka Pharmaceutical, GlaxoSmithKline, Shionogi, Dainippon-Sumitomo Pharma, Eli Lilly and Company, Mochida Pharmaceutical, Meiji-Seika Pharma, and Yoshitomi Yakuhin and speakers honoraria from Otsuka Pharmaceutical, Eli Lilly and Company, Shionogi, GlaxoSmithKline, Yoshitomi Yakuhin, Dainippon-Sumitomo Pharma, Meiji-Seika Pharma, Abbvie, MSD, and Janssen Pharmaceutical. Dr Gerretsen has received fellowship support from the CAMH Foundation, OMHF, and the CIHR Foundation. Dr Mamo has received investigator-initiated grant support from Pfizer. No other disclosures were reported.
Funding/Support: This work was funded by CIHR grant MOP-97946 (Drs Graff-Guerrero and Mamo), US National Institutes of Health grant RO1MH084886-01A2 (Drs Graff-Guerrero and Mamo), CIHR fellowship (Dr Nakajima), Government of Canada postdoctoral research fellowships (Dr Suzuki), the Japanese Society of Clinical Neuropsychopharmacology (Dr Suzuki), Japan Society for the Promotion of Science (Dr Nakajima), Kanae Foundation (Dr Suzuki), Mochida Memorial Foundation (Dr Suzuki), Nakatomi Foundation (Dr Nakajima), and an Ontario Graduate Scholarship (Mr Caravaggio).
Role of the Funder/Sponsor: The funding organizations had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.
Previous Presentations: Some data from this study were presented at the 2013 Annual Meeting of the American Association for Geriatric Psychiatry; March 15, 2013; Los Angeles, California; the 2014 Annual Meeting of the Society of Biological Psychiatry; May 8, 2014; New York, New York; the 29th Collegium Internationale Neuro-Psychopharmacologicum; June 24, 2014; Vancouver, British Columbia, Canada; and the 53rd Annual Meeting of the American College of Neuropsychopharmacology; December 8, 2014; Phoenix, Arizona.
Additional Contributions: The positron emission tomography center staff at the Centre for Addiction and Mental Health, including Alvina Ng, BS, and Laura Nguyen, BS, provided technical assistance in data collection. The Multimodal Imaging Group Staff at the Centre for Addiction and Mental Health, including Thushanthi Balakumar, Zhe Feng, Kathryn Kalahani-Bargis, and Alex Naber, assisted in participants’ recruitment and data administration.