Table 5.

Studies examining the relationship between prolactin and tardive dyskinesia.

Study and authors	Patient sample	Results
Glazer et al., 1981 [100]	19 men with TD; 29 postmenopausal women with TD; 21 men without TD	Prolactin levels were higher in women, but not in men, with severe TD compared to those with mild TD
Csernansky et al., 1986 [75]	33 male patients with schizophrenia on treatment; 8 off treatment; 18 normal male controls	“Prolactin index” (plasma prolactin divided by plasma neuroleptic activity) was negatively correlated with the severity of TD in younger patients
Monteleone et al., 1988 [46]	9 patients with schizophrenia and TD; 7 with schizophrenia alone; 10 healthy controls; challenge with sodium valproate 800 mg	Patients with schizophrenia and TD, but not schizophrenia alone, showed a decrease in prolactin following valproate administration; this decrease was correlated with the severity of TD as measured by the Abnormal Involuntary Movement Scale
Shim et al., 2005 [45]	Patients with schizophrenia with and without TD; challenge with the serotonin agonist and dopamine antagonist buspirone	Prolactin response to buspirone decreased in patients with TD
Asnis et al., 1979 [101]	6 patients with tardive dyskinesia, on and off medication, and following a challenge with haloperidol 0.5 mg i.m.; healthy controls	No difference in prolactin levels between the groups in any of the conditions
Ettigi et al., 1976 [102]	17 patients with “chronic schizophrenia” (4 of whom had oral TD) and 21 normal controls; challenge with apomorphine 0.75 mg s.c.	No difference in prolactin levels between patients and controls, either baseline or after apomorphine challenge