I haven’t researched the issue, so I don’t have hard statistics. In my experience, and based on conversations with the professionals that I know (psychologists and social workers), the incidence of inappropriately medicating is currently extremely low.
Usually, the decision to medicate is done either in conjunction with a professional such as a psychologist or social worker or at their recommendation. So using them as proof that there isn’t inappropriate medicating is like asking the wolf to guard the chicken coop.
That is not to say they are always or even usually wrong to medicate, only that you cannot use their words to substantiate your claim.