UNAUDITED PRO FORMA CONDENSED COMBINED FINANCIAL INFORMATION Introduction On

UNAUDITED PRO FORMA CONDENSED COMBINED FINANCIAL INFORMATION

On June 2, 2025, atai Beckley N.V. ("atai", f/k/a atai Life Sciences N.V.) entered into a share purchase agreement with Beckley

Psytech Limited ("Beckley Psytech") and certain selling shareholders of Beckley Psytech, pursuant to which atai agreed to acquire from the shareholders of Beckley Psytech, excluding atai (the "Sellers"), the entire issued share capital of Beckley

Psytech not already owned by atai ("Beckley Shares") by issuing to the Sellers 105,044,902 ordinary shares in the capital of atai with a nominal value of 0.10 per share ("atai Ordinary Shares") (such transaction, the "Acquisition"). Subsequently, on

October 23, 2025, atai entered into a side letter deed to the Share Purchase Agreement (the "SPA Amendment", collectively with the initial share purchase agreement, the "Share Purchase Agreement") with Beckley Psytech, pursuant to which the number of

atai Ordinary Shares to be issued to the Sellers was reduced, on a pro-rata basis, to 103,823,190 atai Ordinary Shares (the "Consideration Shares") as an adjustment for agreed leakages under the Share Purchase Agreement. Prior to the closing of the

Acquisition, in October 2025, Beckley Psytech effected a carve-out, pursuant to which Eleusis Holdings Limited and its subsidiaries ("Eleusis") were carved out from Beckley Psytech by way of a dividend in specie of all of the issued shares in Eleusis

such that the shareholders of Beckley Psytech immediately prior to the Beckley Carve-Out each received a pro-rata equity holding in Eleusis (the "Beckley Carve-Out"). The Acquisition was completed on November 5, 2025 (the "Closing"). Upon completion

of the Acquisition, Beckley Psytech and its subsidiaries ("Beckley Group") became wholly-owned subsidiaries of atai. Following the Closing, atai and its subsidiaries, including the Beckley Group (the "Combined Group") was renamed to "Atai Beckley

The unaudited pro forma condensed combined statement of operations has been prepared by atai in accordance with Regulation S-X

Article 11, Pro Forma Financial Information ("Article 11"). The following unaudited pro forma condensed combined statement of operations gives effect to the Acquisition and other related transactions, including the Promissory Note (defined in Note

1). The Acquisition has already been reflected in the historical audited consolidated balance sheet of atai as of December 31, 2025. Therefore, no unaudited pro forma condensed combined balance sheet

as of December 31, 2025 has been presented herein.

The following unaudited pro forma condensed combined statement of operations for the year ended December 31, 2025 combines the

historical consolidated statement of operations of atai for the year ended December 31, 2025 (which includes historical consolidated financial data of Beckley Psytech from Closing to December 31, 2025) and the unaudited historical consolidated

financial data from continuing operations of Beckley Psytech for the period from January 1, 2025 to the Closing, and depicts adjustments reflecting the accounting for the Acquisition and related transactions, including the Promissory Note, assuming

that those adjustments were made as of January 1, 2025 ("transaction accounting adjustments"). These unaudited pro forma condensed combined financial information and related notes have been derived from and should be read in conjunction with:

The unaudited pro forma condensed combined financial information and related notes should also be read in conjunction with:

The transaction accounting adjustments to the unaudited pro forma condensed combined statement of operations is based on the

assumptions described in the accompanying notes. The unaudited pro forma condensed combined statement of operations is not necessarily indicative of the financial position or results of operations in the future periods or the result that actually

would have been realized had atai and Beckley Psytech been a combined organization during the year ended December 31, 2025.

UNAUDITED PRO FORMA CONDENSED COMBINED STATEMENT OF OPERATIONS

FOR THE YEAR ENDED DECEMBER 31, 2025

(in thousands of dollars, except shares and per share amounts)

See accompanying notes to the unaudited pro forma condensed combined financial information.

NOTES TO THE UNAUDITED PRO FORMA CONDENSED COMBINED FINANCIAL INFORMATION

1. Description of the Acquisition

On June 2, 2025, atai, the Sellers and Beckley Psytech entered into the Share Purchase Agreement, pursuant to which atai agreed to

acquire the Beckley Shares from the Sellers. Prior to entering into the Share Purchase Agreement, on January 3, 2024 atai (i) entered into a subscription and shareholders' agreement (the "SSA") with Beckley Psytech, pursuant to which atai acquired 24,096,385 newly issued series C preferred shares of Beckley Psytech (the "Series C Shares"), and (ii) received an equity warrant instrument, pursuant to which atai acquired 24,096,385 warrants to purchase an

amount of Series C Shares, as well as additional warrants to be issued to atai in the event that Beckley Psytech issues equity or equity linked securities pursuant to a deferred equity arrangement in connection with a prior acquisition made by

Beckley Psytech. See below under "Pre-Existing Investment in Beckley Psytech." As of immediately prior to the Closing, atai held a 33.7% investment in Beckley

Upon Closing on November 5, 2025, the following was effected:

Replacement Awards and Consideration Shares

The Share Purchase Agreement contains provisions relating to the treatment of the holders of Beckley Options (the "Beckley

Optionholders"). Certain Beckley Optionholders that held Vested and In-the-money Beckley Options at Closing received, at atai's sole discretion, either (i) Replacement Awards, (ii) Consideration Shares (with such number of Consideration Shares issued

adjusted to reflect the payment by atai of certain employment taxes arising on the cancellation of Beckley Options in exchange for Consideration Shares and the exercise price of such options), or (iii) a combination of the foregoing. Beckley Options

held by any Beckley Optionholder who was a former employee or former contractor of Beckley, or a non-natural person, lapsed at Closing unless exercised (and the exercise price and related taxes paid) prior to Closing. The granting of Replacement

Awards to Beckley Optionholders at Closing reduced the aggregate number of Consideration Shares issued to the Sellers. At Closing, 93,580,831 Consideration Shares were issued to the Sellers, and 8,695,937 atai restricted stock units and 1,546,253

atai stock options were granted as Replacement Awards to certain Beckley Optionholders. Certain Beckley Optionholders received the atai restricted stock units, net of the exercise price and as a result, 6,971,912 atai restricted stock units were

issued by atai to the Optionholders at Closing.

The Consideration Shares and Replacement Awards issued are subject to a lock-up period whereby 1/12th

of the Consideration Shares held by the Sellers following Closing will be released from the lock-up each calendar month, resulting in all of the Consideration Shares then held by the Sellers being freely transferable at the end of the 13th

month following Closing.

Pre-Existing Investment in Beckley Psytech

In January 2024, atai and Beckley Psytech entered into (i) the SSA, pursuant to which atai acquired a

total of 24,096,385 newly issued Series C Shares and (ii) a secondary sale purchase agreement ("Secondary Sale SPA"), pursuant to which atai acquired a total of 11,153,246 ordinary shares of Beckley Psytech, all of which were re-designated into

Series C Shares. Additionally, in connection with the SSA, atai executed a deferred payment escrow agreement (the "Escrow Agreement"), deposited $15.0 million into an escrow account in exchange for a corresponding number of Series C Shares, and

recognized a contingent forward liability of $2.9 million within Other current liabilities in its historical consolidated balance sheet related to the fair value of 9,036,144 Series C Shares (the "Deferred Shares"). Under the terms of the Escrow

Agreement, Beckley Psytech could initially draw down up to $5.0 million from the escrow account, with the remaining balance to be drawn on April 1, 2025. In October 2024, Beckley Psytech drew down $5.0 million from the escrow account and the

associated contingent forward liability of $1.0 million was derecognized. Subsequently, in April 2025, Beckley Psytech drew down $10.0 million from the escrow account and the associated contingent forward liability of $1.9 million was derecognized.

As of the Closing, atai had a total pre-existing investment in Beckley Psytech of 33.7%. The investment in Beckley Psytech Series C Shares is accounted for in accordance with the alternative measurement under Accounting Standards Codification ("ASC")

321, Investments-Equity Securities ("ASC 321") and included in Other investments in atai's historical consolidated balance sheet.

Additionally, in connection with the SSA, on January 3, 2024, atai entered into an agreement with Beckley Psytech (the "Initial

Warrant Agreement") pursuant to which it received warrants to purchase 24,096,385 Series C Shares (the "Beckley Warrants"), which were accounted for under the alternative measurement in accordance with ASC 321 and included in Other investments in

atai's historical consolidated balance sheet.

Pursuant to the Initial Warrant Agreement, atai also received the right to additional warrants (the "Additional Beckley Warrants") to

purchase Series C Shares in the event Beckley Psytech issued equity or equity linked securities pursuant to a deferred equity arrangement in connection with Beckley Psytech's prior acquisition of Eleusis. The Additional Beckley Warrants meet the

definition of a derivative instrument under ASC 815, Derivatives and Hedging ("ASC 815"), and were included in Other investments held at fair value in atai's historical consolidated balance sheet, with subsequent changes in fair value being reflected

through atai's historical consolidated statements of operations in the Change in fair value of assets and liabilities, net. In May 2024, Beckley Psytech issued equity pursuant to the deferred equity arrangement, and atai received 4,393,400 of

Additional Beckley Warrants. As of the Closing, atai had an aggregate 28,489,785 of Beckley Warrants in a carrying amount of $8.5 million. As of the Closing, atai estimated zero value of the Additional Beckley Warrants, which were no longer expected

to be issued considering certain provisions of the Share Purchase Agreement. As a result, atai recognized a loss of $2.8 million during the year ended December 31, 2025.

Pursuant to the Initial Warrant Agreement, the Beckley Warrants and the Additional Beckley Warrants, to the extent unexercised,

automatically lapsed and were cancelled in connection with the Closing. As of the Closing, no Beckley Warrants or Additional Beckley Warrants had been exercised.

On August 13, 2025, atai and Beckley Psytech entered into a senior promissory note (the "Promissory

Note"), pursuant to which atai advanced an aggregate principal amount of up to $10.0 million to Beckley Psytech to be used for the achievement of certain development milestones of BPL-003. The Promissory Note bears interest at a rate equal to the

lesser of 12% per annum and the highest rate permitted by applicable law. The outstanding principal balance of the Promissory Note and all accrued but unpaid interest are due and payable in full on the earlier of (i) the payment of the Break Fee,

(ii) three hundred sixty-four days from the date of the first advance, and (iii) the occurrence of an event of default pursuant to the Promissory Note. The Promissory Note and the related interest were effectively

settled upon Closing since the transaction became an intercompany transaction upon the Closing and was eliminated in the postcombination financial statements of the Combined Group. Therefore, the settlement of the

Promissory Note of $10.0 million and related interest was included as part of the purchase consideration (see Note 5).

Payable to Beckley Psytech

In connection with a public offering completed by atai in October 2025 (the "October 2025 Public Offering"), Beckley Psytech

incurred $0.2 million in professional fees on behalf of atai. As this represented a transaction cost related to atai's October 2025 Public Offering, atai recognized this as a deduction from the proceeds received within additional paid-in capital and

recorded a payable of $0.2 million to Beckley Psytech. Upon the consummation of the Acquisition, this became an intercompany relationship and was effectively settled at Closing. Therefore, the settlement of atai's payable to Beckley Psytech of $0.2

million was deducted from the purchase consideration (see Note 5).

2. Historical Beckley Psytech

The unaudited historical consolidated financial data from continuing operations of Beckley Psytech for the period from January 1, 2025

to November 5, 2025 presented herein does not include the unaudited results of Eleusis as Beckley Psytech determined that Eleusis met the requirement to be presented as discontinued operations as of the date of the Beckley Carve-Out, and was prepared

in pound sterling ("GBP"), the presentational currency, and on the basis of IFRS accounting standards ("IFRS") as issued by the International Accounting Standards Board ("IASB").

For purposes of preparing the unaudited pro forma condensed combined statement of operations, all of Beckley Psytech's unaudited

historical consolidated financial data for the period from January 1, 2025 to November 5, 2025 was converted to USD using the average exchange rate for the period of 1.3173 USD per GBP.

The following table reflects the conversion of the unaudited historical consolidated financial data from continuing operations of

Beckley Psytech to USD (in thousands).

3. Basis of Pro Forma Presentation

The unaudited pro forma condensed combined statement of operations has been prepared by management in accordance with Article 11, and

is presented in USD. The adjustments presented in the unaudited pro forma condensed combined statement of operations have been identified and presented to provide relevant information necessary for an understanding of the Combined Group after the

consummation of the Acquisition and other related transactions. The unaudited pro forma condensed combined statement of operations reflects certain adjustments to convert the unaudited historical consolidated financial data of Beckley Psytech under

IFRS to GAAP and to align the financial information with atai's accounting policies (see Note 6(d)). These adjustments reflect atai's best estimates based on the information currently available.

The unaudited pro forma condensed combined statement of operations for the year ended December 31, 2025 reflects adjustments that give

effect to atai's results of operations as if those adjustments for the Acquisition and other related transactions were made on January 1, 2025.

The unaudited pro forma condensed combined statement of operations does not give effect to any anticipated synergies, operating

efficiencies, tax savings, or cost savings that may be associated with the Acquisition and other related transactions. In addition, the income tax effects of the transaction accounting adjustments are not expected to be meaningful given the combined

entity incurred significant losses during the historical periods presented, and therefore, no income tax adjustments are included in the unaudited pro forma condensed combined financial information. The unaudited pro forma condensed combined

financial information constitutes forward-looking information, is subject to certain risks and uncertainties that could cause actual results to differ materially from those anticipated and should be read in conjunction with the accompanying notes

The transaction accounting adjustments are preliminary and are based upon available information and certain assumptions which

management believes are reasonable under the circumstances and which are described in the accompanying notes to the unaudited pro forma condensed combined statement of operations. Actual results may differ materially from the assumptions within the

accompanying unaudited pro forma condensed combined statement of operations. The final purchase price allocation will be determined when the final purchase consideration has been determined, detailed valuations and any other studies and calculations

deemed necessary have been completed. Therefore, the actual amounts recorded as of the completion of the Acquisition may also differ materially from the information presented in this unaudited condensed combined pro forma information.

4. Accounting Treatment for the Acquisition