Table 1.
Effect of the –141C Ins/Del polymorphism on antipsychotics response in schizophrenic patients based on studies investigating association between DRD2 variants and response to antipsychotic drugs
| Patients (population) | Antipsychotic drug | Treatment duration (weeks) | Response measurement | Genotyped DRD2 polymorphisms | –141C Ins/Del effect | References |
|---|---|---|---|---|---|---|
| 151 schizophrenics; 95 controls (Caucasian) | Clozapine | – | GAS | –141C Ins/Del | No association | [45] |
| 170 schizophrenics; 121 controls (Japanese) | Antipsychotic drugs not specified | – | PANSS | –141C Ins/Del | No association | [46] |
| 49 schizophrenic inpatients (Japanese) | Bromperidol or nemonapride | 3 | BPRS | –141C Ins/Del | Ins allele associated with greater improvement (only for anxiety–depression symptoms) | [47] |
| 73 schizophrenic patients (Japanese) | Risperidone | 8 | PANSS | –141C Ins/Del, Taq1A | Ins-A2/Del-A1 diplotype associated with better response | [48] |
| 135 schizophrenic inpatients (Chinese) | Chlorpromazine | 8 | BPRS | Del (–) genotype associated with higher degree of improvement | [49] | |
| DSM-III-R or DSM-IV schizophrenics (183 Caucasian; 49 African–American) | Clozapine | 6 | BPRS | –141C Ins/Del, Taq1A, Taq1B, and rs1125394 | No association | [50] |
| 61 first-episode schizophrenia patients (41% African–American; 28% Caucasian; 18% Hispanic; 5% Asian; 8% other) | Olanzapine or risperidone | 16 | CGIIS | –141C Ins/Del, –241A>G | –141C Del allele showed significantly longer time to respond relative to Ins/Ins homozygotes | [51] |
| 125 schizophrenia patients (Chinese) | Risperidone | 8 | BPRS | –141C Ins/Del, Taq1B, rs1076562, Taq1A | No association | [52] |
| 128 schizophrenic inpatients (Han Chinese) | Aripiprazole | 4 | PANSS | –141C Ins/Del, Taq1A, C957T, Ser311Cys | No significant effect | [53] |
–141C Ins/Del (rs1799732); Taq1A (rs1800497); Taq1B (rs1079597); –241A>G (rs1799978); 957C>T (rs6277); Ser311Cys (rs1801028).
BPRS, brief psychiatric rating scale; CGIIS, clinical global impression improvement scale; DRD2, dopamine receptor D2; DSM-IV; Diagnostic and Statistical Manual of Mental Disorders, fourth edition; DSM-III-R, revision of DSM-III; GAS, global assessment scale; PANSS, positive and negative symptom scale.