Do you mean like, a poisonous apple, or like, a people-killing factory? If you mean the latter, I used to draw those with stick figures =D
Not anything to crazy.. just like a person has issues anxiety, paranoia delusions, bad anger and is actually thinking about killing someone and the psychiatrist suspects it and and asks and the person just caves in and tells them there plan. Does psychiatrist have to tell anyone and what are the chances of them sending you to a looney bin for it
Psychologists/psychiatrists have a doctor-patient confidentiality agreement but are allowed to report a person to the authorities if they think they are a danger to themselves or others. Some groups/corporations/states may encourage or require that they do. But it comes down to a matter of judgment on the psych's part, of how serious of a threat it is, and what the best course of action would be.
If you have established you are venting that's fine, but the patient/therapist confidentiality rule is automatically broken if the therapist/doctor believes you are LITERALLY going to be danger to yourself or someone else, and has the right to commit you to a hospital, cops and all, against your will. Make sure you have a good repore established with whom you are working.
depending on the state you live in there are laws to protect your confidentiality when speaking with a psychologist or therapist. Most of the time, therapists by law are required to report to the authorities or your parents if you feel homicidal, if you are currently being sexually abused/raped, or if you are a threat to yourself (this can include some severe forms of self-mutilation). All of this varies depending on where you live, but most states agree that those specific issues require a therapist to breech their patient's confidentiality.