May 7, 2021 – Toronto, Ontario – Greenbrook TMS Inc. (TSX: GTMS, NASDAQ: GBNH) (“Greenbrook” or the “Company”) announces today that it will postpone the release of its first quarter 2021 operational and financial results, originally scheduled for Wednesday, May 12, 2021. Greenbrook will now release its first quarter 2021 operational and financial results after market hours on Friday, May 14, 2021.

FIRST QUARTER 2021 CONFERENCE CALL DETAILS

Bill Leonard, President and Chief Executive Officer, and Erns Loubser, Chief Financial Officer, will host a conference call at 10:00 a.m. (Eastern Time) on Monday, May 17, 2021 to discuss the financial results for the quarter.

Dial in Numbers:

Toll Free North America: (866) 521-4909

Toronto: (647) 427-2311

Webcast:

For more information or to listen to the call via webcast, please visit: https://www.greenbrooktms.com/investors/events

For those that plan on accessing the conference call or webcast, please allow ample time prior to the call time.

Conference Call Replay:

Toll Free (North America): (800) 585-8367

Toronto: (416) 621-4642

Conference ID: 6679987

The conference call replay will be available from 1:00 p.m. ET on May 17, 2021, until 11:59 p.m. ET on June 17, 2021.

About Greenbrook TMS Inc.

Operating through 128 Company-operated treatment centers, Greenbrook is a leading provider of Transcranial Magnetic Stimulation (“TMS”) therapy, an FDA-cleared, non-invasive therapy for the treatment of Major Depressive Disorder and other mental health disorders, in the United States. TMS therapy provides local electromagnetic stimulation to specific brain regions known to be directly associated with mood regulation. Greenbrook has provided more than 620,000 TMS treatments to over 17,000 patients struggling with depression.

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For further information please contact:

Glen Akselrod Investor Relations Greenbrook TMS Inc.

Contact Information: investorrelations@greenbrooktms.com 1-855-797-4867