You can't be careful at all doing this, this is like smoking a cigarette in a dynamite factory.
Using LLMs for therapy is so deeply dystopian and disgusting, people need human empathy for therapy. LLMs do not emit empathy.
Complete disaster waiting to happen for that individual.
Claudes have lots of empathy. The issue is the opposite - it isn't very good at challenging you and it's not capable of independently verifying you're not bullshitting it or lying about your own situation.
But it's better than talking to yourself or an abuser!
Using an LLM for therapy is like using an iPad as an all-purpose child attention pacifier. Sure, it’s convenient. Sure there’s no immediate harm. Why a stressed parent would be attracted to the idea is obvious… and of course it’s a terrible idea.
My experience is that it tries to look at your situation in an objective way, and tries to help you to analyse your thoughts and actions. It comes across as very empathetic though, so there can lie a danger if you are easily persuaded into seeing it as a friend.