Improvements in subjective and objective measures were maintained at 3-month follow-up. Tart et al. replicated the procedures of the first study and randomized 29 participants with height phobia for two sessions of VRE in combination with 50 mg of DCS or placebo. This was the first study, identified in this review, using DCS immediately after the exposure session. The VRE protocol used was the same as in the previous study by Ressler et al.. Participants were selected according to the DSM-IV-TR criteria for acrophobia and a subjective Scopoletin distress score.50 on the Behavioral Avoidance Test. Participants using other psychotropic medications or psychotherapy and previous non-response to exposure therapy for acrophobia were excluded. Response was defined as ����very much improved���� or ����much improved���� on CGI-I. Remission was defined as ����normal���� or ����minimally ill���� on CGIS. Evaluations were performed at baseline, at each treatment session, one week post-treatment and at 1-month follow up. Significant improvements were observed in all measures, with no differences between the groups. The improvement was significant in all outcome measures, but there was no significant statistical difference between the groups on DCS versus Diperodon placebo on BAT, AAVQ, and CGI scores and other measures. The proportions of responders were 81.8% in the placebo group and 66.7% in the DCS group after treatment, and 80.1% in the control group and 75.0% in the DCS group at 1-month follow-up. Regarding the proportion of patients achieving remission, the authors found 63.5% in the placebo group and 60.0% in the DCS group after treatment, and 63.4% in the placebo group and 66.6% in the DCS group at 1-month follow-up. In the study by Nave et al., 20 adults with snake phobia received 50 mg of D-cycloserine or placebor prior to a single session of graded exposure therapy. All of the participants achieved score $18 on the Snake Questionnaire, had not undergone treatment for snake phobia previously, and were suitable for functional magnetic resonance imaging. Participants were assessed one week before and after treatment through clinical examination and the Snake Questionnaire. The DCS and placebo group responded well to the treatment, although the DCS group reached the top of the exposure hierarchy more quickly.