Table 1 Characteristics and results of clinical trials of DCS-augmented CBT for anxiety disorders
From: D-Cycloserine as an augmentation strategy for cognitive behavioral therapy of anxiety disorders
Study | Diagnosis | N | DCS Dose (mg) | Dosing timing (hrs before exposure) | # of DCS doses | CBT type (# of exposure sessions) | Primary measures | Main results (DCS vs. placebo) |
|---|---|---|---|---|---|---|---|---|
Ressler et al., 2004 [53] | Acrophobia | 27 | 50 or 500 | 2-4 | 2 | VRE (2) | SUDS, skin conductance, clinical self-reports | Greater subjective improvement (p < .001); greater decrease in skin conductance fluctuations (p < .05); greater clinical improvement (p < .02) effects were maintained at 3-month follow-up |
Guastella et al., 2007 [54] | Sub-threshold spider phobia | 63 | 50 | 2-3 | 1 | Exposure (1) | SUDS, heart rate | No DCS effects |
Tart et al., 2013 [55] | Acrophobia | 29 | 50 | −0.5a | 2 | VRE (2) | SUDS, CGI-I | No overall DCS effects. |
Smits et al., 2013 [56] | DCS effect on CGI-I significantly moderated by fear level at end of exposure session (b = −.05, p < .01); low levels of fear predicted greater symptom improvement | |||||||
Nave et al., 2012 [57] | Snake phobia | 20 | 50 | 1 | 1 | Exposure (1) | Snake Questionnaire | No overall DCS effects. |
DCS group reached top of fear hierarchy more quickly (p < .05) | ||||||||
Hofmann et al., 2006 [58] | SAD | 27 | 50 | 1 | 5 | Individual/group CBT, emphasis on exposure (5) | SPAI, LSAS | Greater symptom improvement (p’s < .02); effects maintained at 1-month follow-up |
Guastella et al., 2008 [59] | SAD | 56 | 50 | 1 | 4 | Group CBT, emphasis on exposure (4) | SPAI, LSAS | Greater symptom improvement over time (p = .002). |
Rodebaugh et al., in press [60] | SAD | 34 | 250 | 0 | 1 | Exposure (2) | SUDS | Greater reduction in subjective distress between two exposure sessions (d = 1.06) |
Hofmann et al., in press [61] | SAD | 169 | 50 | 1 | 5 | CBT (5) | LSAS, SPDS | Faster symptom improvement, global illness severity and remission status (p’s < .05) |
Wilhelm et al., 2008 [62] | OCD | 23 | 100 | 1 | 10 | Exposure-based behavior therapy (10) | YBOCS | No overall DCS group effect; significant time by group interaction (p = .02), with greater symptom improvement in DCS group at mid-treatment. |
Chasson et al. 2010 [63] | Re-analysis showed DCS increased speed of symptom improvement sixfold during the first half of treatment. | |||||||
Kushner et al., 2007 [64] | OCD | 25 | 125 | 2 | 10 | ERP (10) | YBOCS | Lower drop-out rate (p < .05); symptoms improved more quickly during first 4 sessions (p = .02, d = .77) |
Storch et al., 2007 [65] | OCD | 24 | 250 | 4 | 12 | ERP (12) | YBOCS | No DCS effects. |
Storch et al., 2010 [66] | Pediatric OCD (ages 8–17) | 30 | 25 or 50 | 1 | 7 | ERP (7) | CYBOCS, CGI-S, ADIS-CSR | Small-to-moderate DCS effects (d = .31-.47) |
Otto et al., 2010 [67] | PD, PDA | 31 | 50 | 1 | 3 | Brief CBT (3) | PDSS, CGI-S | Greater symptom and severity reduction (p = .01, d = 1.11), maintained at follow-up (p < .05) |
Siegmund et al., 2011 [68] | PDA | 39 | 50 | 1 | 3 | CBT (3) | PAS, CGI | No overall DCS effects; statistical trend (p = 0.075) in severely ill patients that DCS accelerated symptom reduction |
de Kleine et al., 2012 [69] | PTSD | 67 | 50 | 1 | 7-9 | Prolonged Exposure (7–9) | CAPS | No overall DCS effects; DCS group more likely to show response (odds ratio 2.83, 95 % confidence interval [CI] 1.05–7.61). |
Litz et al., 2012 [70] | PTSD | 26 | 50 | 0.5 | 4 | Brief CBT (4) | CAPS, PTSD Checklist | DCS associated with poorer outcome on all measures |