Table 4A.
Human trials: D-cycloserine (DCS) combined with CBT.
| Disorder | Study design | Outcome (compared to placebo control group) | Reference |
|---|---|---|---|
| Healthy volunteers | DCS or placebo 2–3 h prior extinction training | No effect on fear extinction or fear recovery in healthy volunteers |
(Guastella et al., 2007) |
| Healthy volunteers | DCS, placebo, valproic acid or combination of DCS and valproic acid 1.5 h prior extinction training |
Administration of DCS, valproic acid or DCS/valproic acid combination facilitates fear extinction and protects from reinstatement |
(Kuriyama et al., 2011) |
| Healthy volunteers | DCS or placebo 2 h prior extinction training | No effect on extinction learning and retention in healthy volunteers |
(Klumpers et al., 2012) |
| Acrophobia | DCS or placebo 1 h prior 2 sessions of virtual reality exposure 3 month follow-up |
Reduced fear symptoms in DCS group at all timepoints | (Ressler et al., 2004) |
| Acrophobia | 2 sessions virtual reality exposure plus DCS or placebo after the sessions 1 month follow-up Re-evaulation of (Tart et al., 2013) |
No advantage of DCS over placebo augmented VRE DCS effect depends on success of exposure sessions (within-session fear reduction) |
(Tart et al., 2013) (Smits et al., 2013a) |
| Snake phobia | DCS or placebo 1 h prior a single exposure session | Same level of improvement with DCS, but DCS group achieved fear reduction quicker |
(Nave et al., 2012) |
| Panic disorder | DCS or placebo 1 h prior CBT session 3–5 1 month follow-up |
DCS group showed greater reduction in panic symptom severity at all timepoints |
(Otto et al., 2010c) |
| Panic disorder with agoraphobia | DCS or placebo 1 h prior 3 individual exposure sessions + 8 group CBT sessions 5 months follow-up |
No benefits of DCS at all timepoints, but initial benefical effects in severely symptomatic patients? |
(Siegmund et al., 2011) |
| PTSD | DCS or placebo 1 h prior 10 weekly exposure sessions |
No overall enhancement of treatment effects. Higher symptom reduction in severe cases. |
(de Kleine et al., 2012) |
| PTSD (combat-related) |
DCS or placebo 30 min prior exposure session 2–6 | Weaker symptom reduction compared to placebo group |
(Litz et al., 2012) |
| PTSD | DCS or placebo 1.5 h prior 12 weekly VRE session 6 months follow-up |
DCS group showed earlier and greater improvement as well as higher remission rates |
(Difede et al., 2014) |
| pediatric PTSD | DCS or placebo 12 1 h prior session 5–12 | No difference in symptom reduction, DCS group showed trend for faster response and better retention in 3 month follow-up |
(Scheeringa & Weems, 2014) |
| SAD | 1× psychoeducation; DCS or placebo 1 h prior to 4 h exposure session (5×, individual or group) 1 month follow-up |
Decreased self-reported social anxiety symptoms in DCS group after 1 month |
(Hofmann et al., 2006) |
| SAD | DCS or placebo 1 h prior to 4 h exposure therapy (5×) |
Fewer social fear and avoidance in DCS group. Significant differences in DCS vs placebo following 3rd exposure session. |
(Guastella et al., 2008) |
| SAD | DCS or placebo with CBT | Greater overall rates of improvement and lower post-treatment severity |
(Smits et al., 2013b) |
| SAD | 12 weeks; DCS or placebo 1h prior 5 exposure sessions (12 sessions at all); 6-months follow-up |
Similar response and remission rates, DCS group improved quicker |
(Hofmann et al., 2013b) |
| OCD | D-Cycloserine (DCS) or placebo 4 h prior each exposure session, 12 weeks (one exposure session/week) |
No statistically significant difference. High response rates in treatment and placebo group. |
(Storch et al., 2007) |
| OCD | 2×/week DCS or placebo 2 h prior exposure and response prevention (ERP) sessions (max 10) 3 months follow-up |
Faster improvements in DCS group No difference between DCS and placebo group (no further benefit). |
(Kushner et al., 2007) |
| OCD | 2×/week DCS or placebo 1 h prior 10 ERP sessions 1 month follow-up Re-evaluation of Wilhelm et al., 2008 |
Faster improvements in DCS group No difference between DCS and placebo group (no further benefit). Specific improvements of DCS in the first 5 sessions, 6× faster than placebo group |
(Wilhelm et al., 2008) (Chasson et al., 2010) |
| Pediatric OCD | DCS or placebo 1 h prior weekly session 4–10 (psychoeduction, cognitive training and ERP) for 10 wks |
Modest reduction of obsessive symptoms | (Storch et al., 2010) |
| Pediatric OCD | DCS or placebo 1 h prior session 5–9 ERP-CBT | Significant improvements in OCD severity from posttreatment to 1-month follow-up in severe and difficult-to-treat pediatric OCD |
(Farrell et al., 2013) |
| Pediatric OCD | DCS or placebo immediately after each of 10 CBT (ERP) sessions 1 year follow-up |
both groups improved; no significant advantage of DCS at any timepoint |
(Mataix-Cols et al., 2014) |