Amendment: SEC Form SCHEDULE 13D/A filed by ATAI Life Sciences N.V.

The principal business address of Apeiron and Mr. Angermayer is 66 & 67 Amery Street, SLM1707, Sliema, Malta. The principal business address of each of the remaining Reporting Persons is 440 N Barranca Ave #3391, Covina, CA 91723 USA.

The principal business of Apeiron and Presight II are making investments. The principal business of Presight Management is acting as the general partner of Presight II. Apeiron's sole director is Mario Frendo and his principal business address is 66 & 67 Amery Street, SLM1707, Sliema, Malta. His present principal occupation is Senior Legal Counsel at Apeiron.

No

No

Presight II and Presight Management are organized under the laws of the state of Delaware. Apeiron is organized under the laws of the Malta. Each of Messrs. Hansen and Angermayer is a German citizen. Mr. Frendo is a Maltese citizen.

As of October 20, 2025, the Reporting Persons collectively beneficially own 55,211,716 Ordinary Shares, representing approximately 23.4% of the voting rights attached to the Ordinary Shares. The ownership percentages set forth in this Amendment No. 3 have been calculated on the basis of 235,969,597 Ordinary Shares outstanding as of October 16, 2025, as reported in the Issuer's Prospectus filed pursuant to Rule 424(b)(5) with the Securities and Exchange Commission ("SEC") on October 17, 2025, an additional 2,367,200 Ordinary Shares issued to Apeiron upon the conversion of the previously disclosed convertible promissory notes of the Issuer, and 1,339,663 vested options that are exercisable into one Ordinary share each at an exercise price of $5.68 per Ordinary Share held by Christian Angermayer as of October 16, 2025 (the "Vested Options").

The following table sets forth, as of the date of this Amendment No. 3, the aggregate number of Ordinary Shares and percentage of Ordinary Shares beneficially owned by each of the Reporting Persons, as well as the number of Ordinary Shares as to which each Reporting Person has the sole power to vote or to direct the vote, shared power to vote or to direct the vote, sole power to dispose or to direct the disposition of, or shared power to dispose or to direct the disposition of. Sole Shared Sole power to Shared power power dispose power Amount Percent to vote or to vote or to or to direct to dispose or beneficially of class to direct direct the the to direct the Reporting Person owned the vote vote disposition disposition Apeiron Investment Group, Ltd. 55,211,716 23.4% 0 55,211,716 0 55,211,716 Apeiron Presight Capital Fund II, L.P. 1,799,302 0.8% 0 1,799,302 0 1,799,302 Presight Capital Management I, L.L.C. 1,799,302 0.8% 0 1,799,302 0 1,799,302 Fabian Hansen 1,799,302 0.8% 0 1,799,302 0 1,799,302 Christian Angermayer 56,551,379 24.0% 1,339,663 55,211,716 1,339,663 55,211,716 Presight II is the record holder of 1,799,302 Ordinary Shares. Apeiron is the record holder of 53,412,414 Ordinary Shares which includes 2,367,200 Ordinary Shares issued to Apeiron upon the conversion of the previously disclosed convertible promissory notes of the Issuer. Christian Angermayer may be deemed to beneficially own 1,339,663 Ordinary Shares underlying the Vested Options. Presight Management is the general partner of Presight II. Apeiron and Fabian Hansen are the managing members of Presight Management. Christian Angermayer is the controlling shareholder of Apeiron. As a result, each of Presight Management, Apeiron, Mr. Hansen and Mr. Angermayer may be deemed to share beneficial ownership of the securities held by Presight II, and Mr. Angermayer may be deemed to share beneficial ownership of the securities held by Apeiron.

Except as described in this Item 5, none of the Reporting Persons has beneficial ownership of any Ordinary Shares or, except as described in this Schedule 13D, has effected any transaction in the Ordinary Shares during the past 60 days.

No other person is known to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, the Ordinary Shares owned, directly or indirectly, by the Reporting Persons.

N/A

Item 6 of the Schedule 13D is hereby amended and supplemented by the addition of the following: Lock-Up Agreement On October 20, 2025, the Issuer closed a registered offering of 23,725,000 Common Shares at a purchase price of $5.48 per share with gross proceeds of approximately $130 million (the "Offering"). On October 16, 2025, Apeiron entered into a lock-up agreement (the "Lock-Up Agreement") with Jefferies LLC, as underwriter of the Offering. Pursuant to the terms of the form of Lock-Up Agreement, Apeiron has agreed that, for a period ending 90 days after the date of pricing of the Offering, it will not, without the prior written consent of the underwriter of the Offering and subject to certain customary exceptions, not to offer, pledge, sell, contract to sell, sell any option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant to purchase, lend, or otherwise transfer or dispose of, directly or indirectly, any of the Issuer's Ordinary Shares or securities convertible into or exchangeable or exercisable for any of the Issuer's Ordinary Shares (provided, however, that the Lock-Up Agreement shall not apply to transfers of Ordinary Shares acquired in the open market after the completion of the Offering). The foregoing description of the Lock-Up Agreement does not purport to be complete and is qualified in its entirety by the full text of such agreement, which is attached hereto as Exhibit 99.1 and incorporated herein by reference. Other than as described herein, there are no contracts, arrangements, understandings or relationships among the Reporting Persons, or between the Reporting Persons and any other person, with respect to the securities of the Issuer.

Exhibit No Description 99.1 Lock-up Agreement, dated October 16, 2025, between Apeiron and Jefferies LLC