I watched the whole thing, it definitely is.

That video is constantly making "is causing" type statements, but I haven't found a single one of their cited studies that claims a causal link every single one I looked at is just "is associated with" claims.

Their own sources even directly contradict what they're saying in some of them.

They say:

Weed can damage your ability to regulate your emotions and can worsen anxiety or depressive feelings and can escalate into serious mental disorders.

Their source says:

Conclusion: The association between cannabis and anxiety is best explained by anxiety predisposing individuals toward CU as a method of self-medication. A causal relationship in which CU causes AD incidence is less likely despite multiple longitudinal studies suggesting so.”