Kessler RC (2007). The global burden of anxiety and mood disorders: putting the European Study of the Epidemiology of Mental Disorders (ESEMeD) findings into perspective. J Clin Psychiatry 68 (Suppl 2): 10–19.
Institute of Psychiatry, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
Scores of VAMS’s factors, SSPS-N, BSS, arterial diastolic and systolic pressure, heart rate, as well as the SCL and the total number of SF, were transformed by calculating the difference between the score in each phase and the pretest score in the same volunteer. For the analysis, SCL values were converted into natural logarithms (logn). These delta scores were submitted to a repeated-measures analysis of variance (repeated-measures ANOVA), analyzing the factors of phases, groups, and phases by groups’ interaction. In the case where sphericity conditions were not reached, the degrees of freedom of the repeated factor were corrected with the Huynh–Feldt epsilon. Whenever a significant phase by group interaction occurred, comparisons among the groups were made at each phase using a one-factor ANOVA followed by multiple comparisons with the Bonferroni’s test.
Crippa JA, de Lima Osrio F, Del-Ben CM, Filho AS, da Silva Freitas MC, Loureiro SR (2008a). Comparability between telephone and face-to-face structured clinical interview for DSM-IV in assessing social anxiety disorder. Perspect Psychiatr Care 44: 241–247.
Although physiological measures have not shown significant differences among the groups, the self-report of somatic symptoms (BSS) increased significantly only for the SAD patients who received placebo during the test. Following the same rationale as above, it is well-known that more pronounced bodily symptoms may contribute to the clinical diagnosis of SAD, and this result suggests that CBD also protects the patients from their subjective physiological abnormalities induced by the SPST.
Schneier FR (2001). Treatment of social phobia with antidepressants. J Clin Psychiatry 62 (Suppl 1): 43–48.
As observed in another study of SAD patients’ performance on SPST (Crippa et al, 2008b), the present results of the VAMS scale showed that the SAD-PLAC group presented a significantly higher anxiety level and greater cognitive impairment, discomfort, and alert compared with the control group during the test. This was expected as the fear of speaking in public is a cardinal manifestation of SAD (Brunello et al, 2000).
The participants were invited to attend an assessment interview for possible participation in the present study. None of them were under CBT. Assessment of all of them was undertaken by psychiatrists who were trained in administering the Structured Clinical Interview for DSM-IV (SCID I and II; Liebowitz, 1987; Di Nardo et al., 1994; First et al., 1997). The participants completed the first battery of self-report measures before attending the assessment interview. The baseline period for them was a minimum of 3 weeks showing stable FNE scores (Watson and Friend, 1969; the primary outcome measure). Subsequently, after the assessment interview, they rated themselves on the FNE and LSAS (Liebowitz, 1987) over the succeeding weeks (preintervention). All of the participants had a stable FNE score over the 3 consecutive weeks and were therefore scheduled for intervention within a week after the third-baseline measuring point.
In this regard, preliminary findings reported by a study (Bergamaschi et al., 2011) that investigated the efficacy of CBD with patients with SAD are noteworthy. In that study, 12 patients with SAD were provided with a single dose of CBD (600 mg). When the anxiety induced by simulated public speaking was compared between pretreatment and posttreatment, its level showed a significant decrease after the treatment, whereas no such change was observed in the placebo group of 12 other patients.
Figure 2 presents the results of the measurements with LSAS of the level of the symptoms that are associated with SAD. The results were strikingly similar to those shown in Figure 1 . The main effect was statistically significant for MEASUREMENT (F1,35 = 10.35, p = 0.003, η p 2 = 0.023) but not for PARTICIPANT (F1,35 = 0.45, p = 0.57, η p 2 = 0.011). The interaction between these factors was significant (F1,35 = 39.16, p < 0.001, η p 2 = 0.528). The mean LSAS score (SD) of the CBD group was 74.2 (7.5) in the preintervention measurement and 62.1 (8.7) in the postintervention measurement and that of the placebo group was 69.9 (10.3) in the preintervention measurement and 66.8 (11.2) in the postintervention measurement.
Subsequent analyses of simple main effects (using Bonferroni correction), which were performed because of the significant interactions between MEASUREMENT and PARTICIPANT, revealed that the mean score of the CBD group was lower in the postintervention measurement than in the preintervention measurement (p = 0.02), while no such difference was found in the placebo group (p = 0.29). Scores of the participants in the CBD group were lower than those of the placebo group in the postintervention measurement (p = 0.0002), but the scores were not statistically significantly different from one another in the preintervention measurement (p = 0.71).
Materials and Methods
The primary noneuphorizing and nonaddictive compound of cannabis, cannabidiol (CBD), has recently been shown to possess considerable therapeutic potential for treating a wide range of neuropsychiatric disorders (De Gregorio et al., 2019). They include chronic pain (Costa et al., 2007), nausea (Parker et al., 2006), epilepsy (Devinsky et al., 2016), psychosis (McGuire et al., 2018), and anxiety (Scuderi et al., 2009; Whiting et al., 2015). CBD in therapeutics is used within a large therapeutic window, which ranges from 2.85 to 50 mg/kg/day (Whiting et al., 2015; Devinsky et al., 2016). While this fact indicates that its therapeutic dose is still mostly unknown, clinical studies have revealed that CBD could produce analgesic and anxiolytic effects exerted through its interaction with 5HT1A receptors (De Gregorio et al., 2019). As a potential anxiolytic treatment, in particular, it has drawn increasing interest. A review (Blessing et al., 2015) concluded that existing preclinical evidence strongly supports CBD as a treatment for generalized anxiety disorder, panic disorder, obsessive-compulsive disorder, and posttraumatic disorder when administered acutely.