Table 2. Studies included in the systematic review.
| Author | Year | Main outcome | Study sample | Population | SNPs | Association (for main outcome) |
|---|---|---|---|---|---|---|
| Dawson22 | 1995 | SCZ | Multiplex SCZ pedigrees (23)SCZ patients (131)Controls (103) | Caucasian | (AAT)n | (-) |
| Tsai23 | 2000 | SCZ | SCZ patients (127) Controls (146) | Han Chinese | (AAT)n | (-) |
| Leroy24 | 2001 | SCZ; substance abuse; treatment response | SCZ patients (102) Controls (63) | French | rs1049353 | (+) for substance abuse in patients |
| Krebs25 | 2002 | SCZ; cannabis abuse | SCZ cannabis (102) Non-SCZ cannabis (85) Controls (89) | French | (AAT)n | (+) for cannabis-sensitive SCZ patients |
| Ujike16 | 2002 | SCZ; SCZ subcategories | SCZ patients (121) Controls (148) | Japanese | (AAT)n rs1049353 | (+) (AAT)n for hebephrenic SCZ |
| Martinez-Gras26 | 2005 | Substance abuse; PANSS scores; WCST (executive function) | SCZ patients (75 substance abusers/58 non-abusers) (133) | Spanish | (AAT)n | (+) for negative PANSS scale and WCST in substance abusers |
| Ballon17 | 2006 | SCZ; cocaine addiction | SCZ cocaine (45) Non-SCZ cocaine (97) Controls (88) | African-Caribbean | (AAT)n | (+) for cocaine addiction |
| Martinez-Gras5 | 2006 | SCZ; substance abuse | SCZ patients (113) Controls (111) | Spanish | (AAT)n | (+) for schizophrenia |
| Seifert27 | 2007 | SCZ | SCZ patients (104) Controls (140) | German | (AAT)n rs1049353 rs6454674 | (-) |
| Zammit28 | 2007 | SCZ; cannabis use; other phenotype characteristics | SCZ patients (797) Controls (688) | UK | rs1049353 | (-) |
| Chavarria-Siles29 | 2008 | SCZ; SCZ subcategories | SCZ patients (244) SCZ relatives (481) | Costa Rica | (AAT)n | (+) for hebephrenic SCZ |
| Hamdani18 | 2008 | SCZ; cannabis use; treatment response | SCZ patients (133) Controls (141) | French | rs806468 rs1049353 rs806379 rs806380 | (+) rs1049353 for treatment response |
| Monteleone30 | 2010 | SCZ; weight gain | SCZ patients (83) Controls (80) | Italian | rs1049353 | (-) |
| Tiwari19 | 2010 | Weight gain | SCZ patients (183) | German/U.S. | rs806368 rs1272071 rs1049353 rs806369 rs806370 rs806374 rs806375 rs806377 rs806378 rs2023239 rs806380 rs806381 rs7752758 rs12528858 rs12205430 rs6914429 rs2180619 rs754387 rs9450902 rs10485170 | (+) rs806378 in patients of European ancestry treated with clozapine or olanzapine |
| Ho31 | 2011 | Cannabis abuse; MRI; neurocognitive assessment | SCZ patients (235) | U.S. | rs806365 rs7766029 rs806366 rs806368 rs12710071 rs1049353 rs806374 rs806375 rs806376 rs6454672 rs9450898 rs806380 | (+) rs7766029/rs12720071/rs9450898 for MRI findings |
| Park32 | 2011 | Weight gain (olanzapine) | SCZ patients (78) | Korean | rs806368 rs4707436 rs1049353 | (-) |
| van Winkel33 | 2011 | Psychosis; positive schizotypy; cannabis use | Patients with psychosis (801)Unaffected siblings (740) | Netherlands and Belgium | rs2023239 rs806379 rs1535255 rs6454674 rs806308 rs806377 rs1049353 rs6928499 | (-) |
| Schennach34 | 2012 | Treatment response | SCZ patients (274) Controls (427) | German | rs1049353 | (-) |
| Tiwari35 | 2012 | TD | SCZ patients (191) | U.S./Canadian | rs806369 rs1272071 rs1049353 rs806369 rs806370 rs806374 rs806375 rs806377 rs806378 rs2023239 rs806380 rs806381 rs7752758 rs12528858 rs12205430 rs6914429 rs2180619 rs754387 rs9450902 rs10485170 | (+) rs806374 |
| Costa36 | 2013 | SCZ | SCZ patients (170) Controls (350) | Italian | rs1049353 rs7766029 rs806366 rs12720071 rs806380 rs9450898 rs806375 rs806368 rs6454672 rs806374 rs806365 rs806376 | (-) |
| Yu37 | 2013 | MetS | SCZ patients (407) | Belgium | rs6454674 rs6928499 rs806379 rs1535355 rs806377 rs1049353 rs2023239 | (+) rs6928499 rs1535355 rs2023239 |
| Bae21 | 2014 | SCZ | SCZ patients (337) Controls (394) | Korean | rs806376 rs806368 rs806366 rs6689530 rs34570472 | (-) |
| Copoglu38 | 2015 | SCZ; symptoms | SCZ patients (66) Controls (65) | Turkish | rs6454674 rs806368 rs1049353 | (+) rs6454674 for SCZ symptoms |
| Suárez-Pinilla39 | 2015 | Cannabis use; MRI; BMI; clinical psychopathology | First-episode psychosis patients (65) | Spanish | rs1049353 rs1535255 rs2023239 | (+) all SNPs for MRI and clinical psychopathology |
BMI = body mass index; SCZ = schizophrenia; MetS = metabolic syndrome; MRI = magnetic resonance imaging; PANSS = Positive and Negative Syndrome Scale; SNP = single nucleotide polymorphism; TD = tardive dyskinesia; WCST = Wisconsin Card Sorting Test.