Compared to immediate risks such as attacking other patients, staff or ripping IVs out, antipsychotics, despite the increased risks are justified in delirium or dementia patients. Simply because the risk of not taking them is worse. GAF should be less than 20. (20-40 IMHO is a grey are whether or not to use them).
They however are not justified in cases where doctors give them out in a patient with Alzheimer's where the person is not acting out in a manner dangerous to self or others.