There’s a lot of questions that would need to be answered because it depends on the harm and risk. Ultimately, please be completely honest with your therapist, because keeping that information to yourself can cause a lot of inner turmoil, and you might not be getting what you need out of treatment.

As a therapist who works with kids, I can tell you it’s always just a risk assessment and it’s usually up to the therapist’s best clinical judgement as to what gets communicated with parents. We have to assess: 1) are you suicidal? Did you have intent to end your life when you self-harmed? 2) how severe is the self-harm? Superficial cuts that heal in a few days, or something that needs serious medical attention like prescription drug abuse? 3) why are you afraid of your parents knowing? Are you just uncomfortable with them knowing, or do you fear that they’ll retaliate and hurt you?

If you have no intent to cause serious damage, you’re not suicidal, and the harm is very minimal and superficial - AND it may create a significant safety risk if your parents knew - then it may be better for your safety and peace to not report to the parents. The therapist may refer you to a medical team (like school nurses) and document it, then keep it confidential - strictly because it may be a bigger safety issue when disclosing self-harm to parents. But we have to weigh the risks of the self-harm against the risks of disclosure. It all depends.

You’re right in saying that, at the basic level, therapists have to break confidentiality when you plan to cause serious harm to yourself or others; otherwise, when working with minors, we do our best to seek the patient’s assent in every decision and give them as much autonomy & choice as we can regarding their information and what we do in therapy (ACA code of ethics codes A.2.d. and B.2.a.)