“…However, rarer syndromes have also been associated with clozapine withdrawal, such as delirium [ 3 ], catatonia [ 4 ], serotonin syndrome [ 5 ], NMS [ 6 ], and movement disorders such as dystonias and dyskinesias [ 7 ]. The diverse presentation of clozapine-withdrawal states is likely secondary to its broad pharmacological profile, with antagonistic effects in serotonergic, cholinergic, dopaminergic, and histaminergic receptors leading to rebound hyperactivity in these systems, along with rebound dysregulation of gamma-aminobutyric-acid- (GABA-) ergic pathways as a result of clozapine's activity on GABA receptors [ 4 , 8 , 9 ]. Treatment of clozapine-withdrawal syndromes should be targeted at particular neurotransmitter systems depending on the symptoms and signs observed; for example, benztropine and cyproheptadine have been suggested as treatments for cholinergic and serotonergic rebound symptoms, respectively [ 5 , 9 ].…”