Background: Psychiatric treatment of mentally handicapped patients is still in its infancy because these patients are diagnosed by means of inadequate DSM vignettes that were not developed for such a homogeneous group and that do not have the status of diagnoses based on aetiology and pathophysiology.
Aim: To raise awareness that the psychiatrist dealing with this group of patients needs to have a thorough knowledge of the syndromes involved which can be accompanied by psychiatric and somatic comorbidity and also needs to have expertise in linked disciplines such as genetics, epileptology and pharmacology.
Method: On the basis of the international scientific literature an attempt was made to identify the rationale that underlies the current practice of treating challenging behaviour with a fairly random selection of psychotropics.
Result: A diagnostic algorithm was formulated which can help the psychiatrist to provide evidence-based specialised advice on treatment and which can also prevent the occurrence of harm or damage.
Conclusion: The top-down orientation of current diagnostic procedures, which tries to link symptoms to an underlying pathology, should be counterbalanced by a bottom-up approach in which the aetiology is the starting point. If this principle is observed, a well-founded proposal about treatment can sometimes be put forward. In all other cases treatment at present is little more than symptomatic pharmacotherapy involving a few well-documented psychotropics.