709Medication-Induced Movement
Disorders and Other Adverse
Effects of Medication
Medication-induced  movement disorders are included in Section II because of
their frequent importance in 1)  the management by medication of mental disorders or oth-
er medical conditions and 2) the differential diagnosis of mental disorders (e.g., anxiety
disorder versus neuroleptic-induced akathisi a; malignant catatonia versus neuroleptic
malignant syndrome). Although these moveme nt disorders are labeled “medication in-
duced,” it is often difficult to establish the causal relationship between medication expo-
sure and the development of the movement di sorder, especially because some of these
movement disorders also occu r in the absence of medicati on exposure. The conditions
and problems listed in this ch apter are not mental disorders.
The term neuroleptic  is becoming outdated because it highlights the propensity of an-
tipsychotic medications to cause abnormal movements, and it is being replaced with the
term antipsychotic  in many contexts. Nevertheless, the term neuroleptic remains appropri-
ate in this context. Although newer antipsychotic medications may be less likely to cause
some medication-induced move ment disorders, those disorders still occur. Neuroleptic
medications include so-called conventional, “t ypical,” or first-gene ration antipsychotic
agents (e.g., chlorpromazine, haloperidol, fl uphenazine); “atypical” or second-generation
antipsychotic agents (e.g., clozapine, risperidone, olanzapine, quetiapine); certain dopa-
mine receptor–blocking drugs used in the tr eatment of symptoms such as nausea and gas-