Could an adult niece of a man be accused of Münchausen by Proxy syndrome if she is extremely obsessed with his well being and insists she knows more than the professionals?

Answer 1

What you give in the question doesn't really leap out as a convincing case of Münchausen by Proxy syndrome. It is psychiatrically and legally a highly controversial diagnosis. Ordinary Münchausen syndrome (not by proxy) involves the afflicted person feigning medical or psychological symptoms in order to get the sympathy given to people who are ill, and this can involve producing real symptoms by misusing various drugs or other things. Assuming the sick role is the motivation. Other kinds of motivations, like insurance claims, are not present.

Münchausen by Proxy syndrome is when a person takes steps to feign or actually produce symptoms in another person in order to assume the sick role vicariously through the other person. The disorder is believed to be suffered mostly by mothers of young children, and the mothers are able to control the appearance of hard to explain symptoms in the children in various ways. It is sometimes suspected in mothers who have several children all of whom died from SID (Sudden Infant Death). In the well known movie The Sixth Sense, there is a chilling story line built on a person with Münchausen by Proxy syndrome. See Discussion for summary.

The woman in the question may be obsessed, and perhaps hysterical, but if the uncle is otherwise unharmed, unaffected, or even bemused by his out of control niece, then Münchausen by Proxy doesn't seem to fit. There may be elements of Narcissistic Disorder, and a careful mental health assessment and evaluation would clear this up. Typically persons suffering with Münchausen related disorders use deceit and even criminal harm to self or others in order to get the sympathy of people in the medical professions; they would not go out of their way to claim to know more than the doctors. They want to assume the sick role, not a superior role.