Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Total revenue	$ 719	$ 273	$ 2,274	$ 273
Operating expenses:
Research and development	11,092	12,605	22,420	24,136
General and administrative	14,900	13,397	25,497	25,952
Total operating expenses	25,992	26,002	47,917	50,088
Loss from operations	(25,273)	(25,729)	(45,643)	(49,815)
Other expense, net:
Interest income	248	118	434	425
Interest expense	(264)	(702)	(1,164)	(1,388)
Benefit from research and development tax credit	28	381	56	586
Change in fair value of assets and liabilities, net	(7,005)	(30,600)	(12,502)	(31,800)
Gain on other investments	3,794	0	3,794	0
Change in fair value of digital assets, net	1,428	0	1,216	0
Loss on extinguishment of debt	(1,317)	0	(1,317)	0
Foreign exchange gain (loss), net	1,460	122	1,916	(94)
Other expense, net	(752)	(667)	(752)	(672)
Total other expense, net	(2,380)	(31,348)	(8,319)	(32,943)
Net loss before income taxes	(27,653)	(57,077)	(53,962)	(82,758)
Provision for income taxes	(93)	(19)	(249)	(15)
Losses from investments in equity method investees, net of tax	0	(273)	0	(1,974)
Net loss	(27,746)	(57,369)	(54,211)	(84,747)
Net loss attributable to noncontrolling interests	(17)	(57)	(51)	(722)
Net loss attributable to ATAI Life Sciences N.V. stockholders	$ (27,729)	$ (57,312)	$ (54,160)	$ (84,025)
Net loss per share attributable to ATAI Life Sciences N.V. shareholders - basic	$ (0.14)	$ (0.36)	$ (0.29)	$ (0.53)
Net loss per share attributable to ATAI Life Sciences N.V. stockholders - diluted	$ (0.14)	$ (0.36)	$ (0.29)	$ (0.53)
Weighted average common shares outstanding attributable to ATAI Life Sciences N.V.Stockholders - basic	196,563,699	160,387,701	186,473,494	159,643,518
Weighted average common shares outstanding attributable to ATAI Life Sciences N.V. Stockholders - diluted	196,563,699	160,387,701	186,473,494	159,643,518
License [Member]
Total revenue	$ 0	$ 273	$ 202	$ 273
Research and development services revenue [Member]
Total revenue	$ 719	$ 0	$ 2,072	$ 0