|
| Study and authors | Patient sample | Results |
|
| Segal et al., 2007 [12] | 57 unmedicated male patients with schizophrenia (off medication for at least 3 months); 32 controls | Significantly lower prolactin levels in patients with the paranoid subtype of schizophrenia |
|
| Segal et al., 2004 [32] | 48 first-episode and 38 recurrent patients with schizophrenia | Significantly lower prolactin levels in paranoid schizophrenia compared to schizoaffective and disorganized subtypes; no effect of illness duration on levels |
|
| Segal et al., 2007 [68] | 45 male patients with schizophrenia, receiving risperidone | Significantly greater elevation of prolactin in patients with the paranoid subtype of schizophrenia |
|
| Otani et al., 1996 [69] | 56 unmedicated patients with schizophrenia (28 male, 28 female) | Weak negative correlation between prolactin and hostility scores; no relation with other measures of psychopathology on the Brief Psychiatric Rating Scale |
|
| Newcomer et al., 1992 [70] | 24 patients with schizophrenia on maintenance treatment with haloperidol | Significant positive correlation between prolactin levels and negative symptoms |
|
| Akhondzadeh et al., 2006 [71] | 54 male patients with schizophrenia on maintenance treatment with haloperidol or risperidone; 25 healthy male controls | Significant positive correlation between prolactin levels and negative symptoms |
|
| Rinieris et al., 1985 [72] | Male patients with paranoid schizophrenia with or without “homosexual delusions”; healthy heterosexual controls | Lower prolactin levels associated with delusions having a homosexual content |
|
| Johnstone et al., 1977 [73] | 16 unmedicated male patients with “chronic schizophrenia” | Serum prolactin was negatively correlated with both speech incoherence and total positive symptoms |
|
| Kleinman et al., 1982 [74] | 17 drug-free patients with “chronic schizophrenia” | Inverse relationship between prolactin and total psychotic symptoms but only in those patients who did not show ventricular enlargement on computed tomography |
|
| 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 paranoid symptoms in younger patients receiving treatment |
|
| Prasad, 1986 [76] | 13 patients off medication for 12 months: 4 with positive symptoms, 9 with negative symptoms | Higher prolactin levels in the group with positive symptoms |
|
| Luchins et al., 1984 [77] | 23 patients with schizophrenia | No relationship between prolactin levels and psychopathology |
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