Question: Should I have contact with the doctor who is treating my family member for bipolar disorder?
Answer: The answer to this really depends on the family member with bipolar disorder. There is very strong safeguards in place to protect people's privacy. So if the person who has bipolar disorder does not want their family members or friends to be talking to their treaters who take care of them for their psychiatric problems, that actually will block that path.
The exception to this is family members and friends can provide the treaters with information -- so if you're seeing something that's really concerning you about your family member's behavior, then it's perfectly fine to pick up the phone or talk to the person -- to the treaters. But what you can't do is actually try and influence their decision making or ask the treaters about information about your family member.
The one exception to this of course is children and adolescents who are minors and they're often assumed to be under the guardianship of their parents unless there are some other rules in place or guardianship in place and so on. In those cases, it's perfectly fine for the parents acting in the best interests of the child to be communicating with your child's treaters and exchanging information and also making medical treatment decisions together with your child's treaters.