Exhibit 15.1

Consent of Independent Registered Public Accounting Firm

Addex Therapeutics Ltd

Geneva, Switzerland

We hereby consent to the incorporation by reference in the Registration Statements on Form F-3 (No. 333-255089) and Form S-8 (No. 333-255124) of Addex Therapeutics Ltd (the Company) of our report dated May 15, 2025, relating to the consolidated financial statements appearing in the Company’s Annual Report on Form 20-F for the year ended December 31, 2024.

BDO AG

​

​

Consent of Independent Registered Public Accounting Firm

Neurosterix US Holding LLC

Delaware, USA

We hereby consent to the incorporation by reference in the Registration Statements on Form F-3 (No. 333-255089) and Form S-8 (No. 333-255124) of our report dated May 15, 2025, relating to the Neurosterix US Holding LLC consolidated financial statements appearing in Addex Therapeutics Ltd’s Annual Report on Form 20-F for the year ended December 31, 2024.

BDO AG

​