In the instance Annakei describes I completely agree that this type of disclosure is appropriate. I guess what I find less appropriate (at least for me) is commiserating with your client about your own history of depression, anxiety, ocd, eating disorder, substance abuse issues, etc. Somehow it seems to me that, although we all are at risk for dealing with at least one of these issues in at least one point during our lives, disclosing the personal experience of such issues tends to discredit the therapist. Although the temptation might be to say, "I understand what you're going through, I've been through it myself and my experience was....," it creates a risk that the client might questions whether the therapist is strong enough to handle what they came in to get help for. Yes, I guess that reflects and reinforces a stigma that therapists aren't supposed to have problems. But if the client is looking for someone to commiserate with, they need a best friend - not a therapist. Somehow describing a situation that you observed or experienced as a situational or external experience seems to be a better choice for illustrating a point in therapy. But that's a generalization and I guess it really does depend on the specific situation. Always good to get supervision/consultation on things like this.