An empath being able to put someone to sleep isnt necessarily a psychic attack though depending on the mechanism, it could just be putting the target in a relaxed/tired enough state that they fall asleep which would explain how Thanos could resist the same way anyone resists falling asleep when extremely tired.
So far the only person with the ability to demonstrably alter subjects conscious mind is Scarlet Witch who successfully did so against every opponent she encountered and successfully touched including Thor which doesn't bode well for the whole non human mind=resistance.
__________________ The end always justify's the means by which they were brought to.
Well, that is the thing. IIRC, it was implied that Mantis putting someone to sleep is her making them relaxed/docile enough to lose consciousness. Because she can't manipulate actual thoughts. Only feelings and emotions. She even makes the distinction herself when describing her powers in GotG 2. At around the 0:40 mark:
What I find funny is that, even though Mantis clarifies it's not mind-reading in the scene, the genius (yeah, being sarcastic here) who uploaded the video still called it that.
__________________ Never take life seriously. Nobody gets out alive anyway.