How do you find out if somebody has been a mental hospital patient?

There is no public or central database that contains information about individuals' mental health histories, including whether they have been patients at mental hospitals. The confidentiality and privacy of mental health information is protected by various laws, such as the Health Insurance Portability and Accountability Act (HIPAA) in the United States.

Mental health records are considered private and can be accessed only with the individual's consent or in specific situations permitted by law, such as a court order or when necessary to protect the individual or others from imminent harm.

If you are looking for information about a person's mental health history, it is important to remember that this information is highly sensitive and should be handled with caution. Disclosing such information without an individual's consent can have legal and ethical consequences, and it can potentially harm the person's privacy and well-being.

It is generally recommended that you obtain information about an individual's mental health history directly from the individual themselves, with their explicit consent, or from qualified healthcare professionals who are authorized to provide such information.