TABLE 1.
Studies characteristics
| Studies | Participants (#) | Duration of chronic pain (in months) | Direction of between‐group differences in depression scores | Direction of between‐group differences in anxiety scores | Medications wash‐out (yes/no); time before scanning session | |
|---|---|---|---|---|---|---|
| CP(F/M) | CTRL(F/M) | |||||
| Fibromyalgia | ||||||
| Gracely et al. (2002) | 16(15/1) | 16(15/1) | Not reported | Not reported | Not reported | Yes; 12 hr |
| Pujol et al. (2009) a | 9(9/0) | 9(9/0) | M = 104 | Not reported | Not reported | Yes; 72 hr |
| Jensen et al. (2009) | 16(16/0) | 16(16/0) | Not reported | Not reported | Not reported | Yes; flexible |
| Burgmer et al. (2012) | 17(17/0) | 17(17/0) | >24 | FM > CTRL | FM > CTRL | Yes; 48 hr |
| Kim et al. (2013) | 21(21/0) | 11 (11/0) | Not reported | FM > CTRL | FM = CTRL | Not reported |
| Schreiber et al. (2017) | 38(33/5) | 15(10/5) | Not reported | FM > CTRL | FM > CTRL | No |
| Low‐back pain | ||||||
| Derbyshire et al. (2002) a | 16(12/4) | 16(11/5) | Not reported | Trend LBP > CTRL | LBP > CTRL | Yes; 2 weeks |
| Baliki et al. (2010) | 16(8/8) | 16(8/8) | Not reported | Not reported | Not reported | Not reported |
| Rodriguez‐Raecke et al. (2014) | 19(12/7) | 21(15/6) | >2 | LBP > CTRL | LBP = CTRL | No |
| Irritable bowel syndrome | ||||||
| Verne et al. (2003) a | 9(6/3) | 9(6/3) | >60 | Not reported | Not reported | Not reported |
| Elsenbruch et al. (2010) a | 15(15/0) | 12(12/0) | >12 | IBS = CTRL | IBS > CTRL | Not reported |
| Bouhassira et al. (2010) a | 19(19/0) | 11(11/0) | M = 216 | IBS = CTRL | IBS = CTRL | Yes; 7 days |
| Guleria et al. (2017) a | 20 (0/20) | 10 (0/10) | M = 28 | Not reported | Not reported | Not reported |
| Neuropathic pain | ||||||
| Albuquerque et al. (2006) | 8(8/0) | 8(8/0) | M = 48 | NP = CTRL | NP > CTRL | Yes; >4 half‐lives |
| Vartiainen et al. (2009) a | 8(7/1) | 11(5/6) | 36–240 | Not reported | Not reported | Not reported |
| Neuropathic pain and fibromyalgia | ||||||
| Hampson et al. (2013) a | 48(48/0) | 13(13/0) | Not reported | Not reported | Not reported | Not reported |
| Total participants | 295(246/49) | 211(167/44) | ||||
a
Studies contributing to the cluster identified in the analysis of Dataset #2 with the coordinate density analysis (ABC). Bibliography in Supporting Information.
Abbreviations: CP, chronic pain patients; CTRL, control individuals; F, female; M, male.