Table. Summary of Sample and Study Characteristics of Included Studies Involving Healthy Volunteers and Patients With Schizophreniaa.
| Source | Sample size, No. | Age, mean (SD), y | Sex, No. male:female | Blinded | Randomized | Placebo condition | Symptom subscales reported | Length of ketamine infusion before symptom assessment, min |
|---|---|---|---|---|---|---|---|---|
| BPRS Studies | ||||||||
| Kraguljac et al,30 2017 | 15 | 24.8 (3.49) | 10:5 | No | No | Saline | Total, positive (2), and negative | NR |
| Kort et al,43 2017 | 31 | 27.0 (4.3) | 19:12 | Double | Yes | Saline | Total | NR |
| Duncan et al,36 2001 | 16 | 33.3 (3.1) | 16:0 | Double | Yes | Saline | Total and negative | 50 |
| Parwani et al,37 2005 | 13 | 31.9 (9.6) | 5:8 | Double | Yes | Saline | Total | 15 |
| Rowland et al,38 2005 | 10 | 24.7 (3.4) | 10:0 | Double | Yes | Saline | Total | 45 |
| Abel et al,42 2003 | 8 | 28.75 | 8:0 | Double | Yes | Saline | Total | 15 |
| Anand et al,44 2000 | 16 | 34.0 (12.0) | 8:8 | Double | Yes | Saline | Positive (1) and negative | 5 |
| Krystal et al,35 1998 | 23 | 30.0 | 19:11 | Double | Yes | Saline | Positive (1) and negative | 60 for both subscales |
| Breier et al,39 1997 | 17 | 30.4 (6.8) | 15:2 | Double | Yes | Saline | Positive (1) | NR |
| van Berckel et al,40 1998 | 18 | 23.7 (2.4) | 18:0 | Double | Yes | NR | Total | 40 |
| Malhotra et al,25 1997 | 16 | 27.8 (1.9) | 12:4 | Double | Yes | Saline | Total and negative | 55 |
| Krystal et al,45 1999 | 20 | 28 | 10:10 | Double | Yes | Saline | Positive (1) and negative | 60 for both subscales |
| Krystal et al,46 2003 | 26 | 29.1 (9) | 19:7 | Double | Yes | Saline | Positive (1) and negative | 80 |
| Micallef et al,47 2002 | 8 | 27.0 | 4:4 | Double | Yes | Saline | Positive (1) and negative | NR |
| Rowland et al,52 2010 | 9 | 30.8 | 4:5 | Double | Yes | Saline | Total | NR |
| Newcomer et al,31 1999 | 15 | 21.7 (3.2) | 15:0 | Double | Yes | Saline | Total and positive (1) | 30 |
| Stone et al,53 2011 | 8 | 28 (5.9) | 8:0 | Double | Yes | Saline | Total | NR |
| Boeijinga et al,48 2007 | 12 | 39.6 (4.8) | 12:0 | Double | Yes | Saline | Total | 30 |
| Abdallah et al,54 2018 | 14 | NR | NR | Single | No | Saline | Total and negative | 120 |
| Passie et al,55 2003 | 12 | 26.8 (3.31) | 12:0 | Double | Yes | Saline | Total | NR |
| Horacek et al,56 2010 | 20 | 29.9 (5.69) | 13:7 | Double | Yes | Saline | Total | NR |
| Morgan et al,57 2011 | 16 | 22.4 | 10:8 | Double | No | Saline | Total | NR |
| PANSS Studies | ||||||||
| Thiebes et al,29 2017 | 24 | 25 (2.64) | 24:0 | Single | Yes | Saline | Total, positive, negative, and factor scores | NR |
| Powers et al,58 2015 | 19 | 27.5 | 10:10 | No | No | Saline | Positive and negative | NR |
| Höflich et al,49 2015 | 30 | 25 (4.58) | NR | Double | Yes | Saline | Total, positive, and negative | NR |
| Nagels et al,59 2011 | 15 | 27 (3.6) | 15:0 | Double | Yes | Saline | Total, positive, and negative | NR |
| Driesen et al,60 2013 | 22 | 29.14 (7.07) | 14:8 | No | No | Saline | Positive and negative | 45 |
| Vernaleken et al,50 2013 | 10 | 24.4 (3.9) | 10:0 | Single | Yes | Saline | Total, positive, and negative | NR |
| Krystal et al,3 2005 | 27 | 30.96 | 16:11 | Double | Yes | Saline | Positive, negative, and factor score | 60 for both subscales |
| Krystal et al,32 2006 | 31 | 28.1 (7.6) | NR | Double | Yes | Saline | Total, positive, negative, and factor score | NR |
| Kleinloog et al,28 2015 | 30 | NR | 15:15 | Double | Yes | Saline | Positive and negative | NR |
| D’Souza et al,51 2012 | 32 | 27 (8.42) | NR | Double | Yes | Saline | Total, positive, and negative | NR |
| Grent-‘t-Jong et al,33 2018 | 14 | 29 (0.9) | 12:2 | Single | Yes | Saline | Total, negative, and positive | NR |
| D’Souza et al,34 2018 | 26 | 29.8 (9.56) | 21:5 | NR | No | Saline | Negative and positive | NR |
| Mathalon et al,61 2014 | 9 | 29.8 (7.9) | 5:4 | Double | Yes | Saline | Total | 1 |
| Dickerson et al,41 2010 | 93 | 24.29 (2.62) | 47:46 | Single | Yes | Saline | Total, positive, negative, and factor score | 45 |
| Schizophrenia (BPRS) | ||||||||
| Lahti et al,26 2001 | 17 | 31.6 (7.8) | 11:6 | Double | Yes | NR | Total, positive (2), and negative | 20 |
| Malhotra et al,25 1997 | 13 | 31.3 (2.8) | 10:3 | Double | Yes | Saline | Total | 55 |
| Malhotra et al,27 1998 | 18 | 34.7 (2.3) | 13:5 | Double | Yes | NR | Positive (1) and negative | 35 |
Abbreviations: BPRS, Brief Psychiatric Rating Scale; NR, not reported; PANSS, Positive and Negative Syndrome Scale.
a
The BPRS measure includes the following positive symptoms (1): conceptual disorganization, suspiciousness, hallucinatory behavior, and unusual thought content; positive symptoms (2): conceptual disorganization, hallucinatory behavior, and unusual thought content; and negative symptoms: blunted affect, emotional withdrawal, and motor retardation. Further details including doses administered are reported in eTables 5 and 6 in the Supplement.