| Document and Entity Information | Dec. 15, 2021 |
| Cover [Abstract] | |
| Entity Address, Country | DE |
| Entity Tax Identification Number | 00-0000000 |
| Amendment Flag | false |
| Entity Central Index Key | 0001840904 |
| Document Type | 8-K |
| Document Period End Date | Dec. 15, 2021 |
| Entity Registrant Name | ATAI LIFE SCIENCES N.V. |
| Entity Incorporation State Country Code | P7 |
| Entity File Number | 001-40493 |
| Entity Address, Address Line One | c/o Mindspace |
| Entity Address, Address Line Two | Krausenstraße 9-10 |
| Entity Address, Postal Zip Code | 10117 |
| Entity Address, City or Town | Berlin |
| City Area Code | +49 89 |
| Local Phone Number | 2153 9035 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Common shares, €0.10 par value per share |
| Trading Symbol | ATAI |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | true |
| Entity Ex Transition Period | false |
