X0206 3 2024-01-01 0 0001735948 Greenbrook TMS Inc. GBNH 0002004693 Mann Surindra Kaur C/O GREENBROOK TMS. 890 YONGE STREET 7TH FLOOR TORONTO A6 M4W3P4 ONTARIO, CANADA 1 0 0 0 Deferred Share Units 0.00 Common Shares 24417 D These deferred share units ("DSUs") were granted on December 15, 2023 pursuant to the DSU Plan for non-employee directors, as described in the Company's 2022 Meeting Information Circular, filed with the Securities and Exchange Commission on May 23, 2023. The DSUs immediately vest upon grant, but holders thereof are not entitled to receive a payment in respect of the value of their DSUs until their tenure on the board of directors ceases. The DSUs do not expire. Ms. Mann will receive a payment in cash at the fair market value of the common shares represented by his or her DSUs generally within ten days of the director's elected redemption date. Each director's elected redemption date will not be earlier than the date the director ceases to hold all positions with the Company and will not be later than December 31 of the year following the year in which the director ceases to hold all positions with the Company. /s/William Leonard, Attorney-in-Fact 2024-01-02