Neural basis of anxiolytic effects of cannabidiol (CBD) in generalized social anxiety disorder: a preliminary report.

Animal and human studies indicate that cannabidiol (CBD), a major constituent of cannabis, has anxiolytic properties. However, no study to date has investigated the effects of this compound on human pathological anxiety and its underlying brain mechanisms. The aim of the present study was to investigate this in patients with generalized social anxiety disorder (SAD) using functional neuroimaging. Regional cerebral blood flow (rCBF) at rest was measured twice using (99m)Tc-ECD SPECT in 10 treatment-naïve patients with SAD. In the first session, subjects were given an oral dose of CBD (400 mg) or placebo, in a double-blind procedure. In the second session, the same procedure was performed using the drug that had not been administered in the previous session. Within-subject between-condition rCBF comparisons were performed using statistical parametric mapping. Relative to placebo, CBD was associated with significantly decreased subjective anxiety (p < 0.001), reduced ECD uptake in the left parahippocampal gyrus, hippocampus, and inferior temporal gyrus (p < 0.001, uncorrected), and increased ECD uptake in the right posterior cingulate gyrus (p < 0.001, uncorrected). These results suggest that CBD reduces anxiety in SAD and that this is related to its effects on activity in limbic and paralimbic brain areas.

Validity of a Brazilian version of the Zung self-rating depression scale for screening of depression in patients with Parkinson's disease.

INTRODUCTION: Parkinson's disease (PD) is a neurodegenerative disorder with prominent motor manifestations and many other non-motor symptoms that significantly decrease quality-of-life and are frequently under-recognized, for example depression. OBJECTIVE: To study the validity of a Brazilian version of the Zung Self-rating Depression Scale (SDS) for the diagnosis of depression in patients with PD. METHODS: We evaluated 78 consecutive non demented patients over the age of 40 with diagnosis of PD at a Movement Disorders Outpatient Clinic, who could read and understand questionnaires. They completed the SDS and the Geriatric Depression Scale with 15 items (GDS-15). The diagnosis of depression was made after a structured clinical interview based on DSM-IV criteria for the diagnosis of major depression (SCID-CV). RESULTS: The prevalence of major depression was 23.1%. Cronbach's alpha was 0.73 and the area under the ROC curve was 0.93 for the SDS. The score index of 55 had a sensitivity of 88.9% and a specificity of 83.3% for the diagnosis of depression. The total scores of the SDS and GDS-15 were highly correlated (0.652, p < 0.0001) and correlated weakly with the scores of a motor scale. DISCUSSION: The SDS is a valid tool for screening depression in patients with PD since the specific SDS index of 55 is adopted. Two shortened versions could be used with good results.

Social anxiety disorder women easily recognize fearfull, sad and happy faces: the influence of gender.

BACKGROUND: It has been suggested that individuals with social anxiety disorder (SAD) are exaggeratedly concerned about approval and disapproval by others. Therefore, we assessed the recognition of facial expressions by individuals with SAD, in an attempt to overcome the limitations of previous studies. METHODS: The sample was formed by 231 individuals (78 SAD patients and 153 healthy controls). All individuals were treatment naïve, aged 18-30 years and with similar socioeconomic level. Participants judged which emotion (happiness, sadness, disgust, anger, fear, and surprise) was presented in the facial expression of stimuli displayed on a computer screen. The stimuli were manipulated in order to depict different emotional intensities, with the initial image being a neutral face (0%) and, as the individual moved on across images, the expressions increased their emotional intensity until reaching the total emotion (100%). The time, accuracy, and intensity necessary to perform judgments were evaluated. RESULTS: The groups did not show statistically significant differences in respect to the number of correct judgments or to the time necessary to respond. However, women with SAD required less emotional intensity to recognize faces displaying fear (p=0.002), sadness (p=0.033) and happiness (p=0.002), with no significant differences for the other emotions or men with SAD. CONCLUSIONS: The findings suggest that women with SAD are hypersensitive to threat-related and approval-related social cues. Future studies investigating the neural basis of the impaired processing of facial emotion in SAD using functional neuroimaging would be desirable and opportune.