https://www.psypost.org/2019/06/first-controlled-study-of-lsd-microdosing-finds-few-benefits-and-some-downsides-53874
And the direct link to the study:
https://www.sciencedirect.com/science/article/pii/S000632231931409X
https://www.psypost.org/2019/06/first-controlled-study-of-lsd-microdosing-finds-few-benefits-and-some-downsides-53874
And the direct link to the study:
https://www.sciencedirect.com/science/article/pii/S000632231931409X