Effect of high-potency cannabis on corpus callosum microstructure.

BACKGROUND: The use of cannabis with higher Δ9-tetrahydrocannabinol content has been associated with greater risk, and earlier onset, of psychosis. However, the effect of cannabis potency on brain morphology has never been explored. Here, we investigated whether cannabis potency and pattern of use are associated with changes in corpus callosum (CC) microstructural organization, in patients with first-episode psychosis (FEP) and individuals without psychosis, cannabis users and non-users. METHOD: The CC of 56 FEP (37 cannabis users) and 43 individuals without psychosis (22 cannabis users) was virtually dissected and segmented using diffusion tensor imaging tractography. The diffusion index of fractional anisotropy, mean diffusivity (MD), axial diffusivity (AD) and radial diffusivity was calculated for each segment. RESULTS: Across the whole sample, users of high-potency cannabis had higher total CC MD and higher total CC AD than both low-potency users and those who never used (p = 0.005 and p = 0.004, respectively). Daily users also had higher total CC MD and higher total CC AD than both occasional users and those who never used (p = 0.001 and p < 0.001, respectively). However, there was no effect of group (patient/individuals without psychosis) or group x potency interaction for either potency or frequency of use. The within-group analysis showed in fact that the effects of potency and frequency were similar in FEP users and in users without psychosis. CONCLUSIONS: Frequent use of high-potency cannabis is associated with disturbed callosal microstructural organization in individuals with and without psychosis. Since high-potency preparations are now replacing traditional herbal drugs in many European countries, raising awareness about the risks of high-potency cannabis is crucial.

A proteomic investigation of similarities between conventional and herbal antidepressant treatments.

Increasing clinical evidence for the effectiveness of herbal antidepressants has led to investigations at the molecular level. Using two-dimensional gel electrophoresis, this study investigated similarities in protein expression between clomipramine, St John's wort and a Chinese herbal formula, xiao-yao-san, often used in mood disorder treatment. HT22 cells, derived from a mouse hippocampal cell line, were treated for 24 h, and protein expression was compared with that of the untreated cells (n = 4/group). Forty-three protein spots were found to be significantly differentially expressed (P < 0.05) in more than one of the treatment groups. Twenty-nine of these were identified using mass spectrometry. The most affected proteins were those involved in the cytoskeleton and energy metabolism, and an up-regulation of vimentin by all three treatments was confirmed by Western blotting. This study provides preliminary evidence for multiple common molecular targets between conventional and alternative antidepressants, which appear to collectively affect neuronal plasticity.

Very early onset seasonal affective disorder: a case study.

A four year old boy was referred from Scotland, with a seasonal pattern of depressive symptoms dating back to infancy and meeting criteria for Major Depressive Disorder with Seasonal Pattern by the age of three years. There was consistency in reports between informants and across contexts and significant improvement with light therapy.

Anxious symptoms influence delayed-type hypersensitivity skin test in subjects devoid of any psychiatric morbidity.

The present study aimed to evaluate the relationship between anxious/depressive symptoms and cell-mediated immunity (Delayed-type Hypersensitivity skin test, DTH) in subjects devoid of any psychiatric morbidity. Forty-eight females and twenty-four males were studied, ages ranging 21-60. These subjects completed the Beck Depression Inventory (BDI) for evaluation of depressive symptoms and the State-Trait Anxiety Inventory (STAIX1, STAIX2) for evaluation of anxious symptoms; subsequently on the same day they were tested for DTH using the Multitest CMI system (Merieux Institute, France). Subjects were split into three groups using the 33rd and 66th percentiles of DTH response (cumulative induration diameter). In females, subjects with larger DTH response (DTH > 8 mm) had significantly lower levels of "state" anxiety (scores at STAIX1; Kruskall-Wallis test, P = .04). On the contrary, no differences were observed between groups considering scores obtained by males at self-evaluation rating scales. Our data seem to support the hypothesis that activity of immune system as measured by DTH skin test may be influenced by affective status in the context of everyday life.