Category Archives: Depression
Antidepressant-like effect induced by Cannabidiol is dependent on brain serotonin levels.
“Cannabidiol (CBD) is a compound of Cannabis sativa with relevant therapeutic potential in several neuropsychiatric disorders including depression. CBD treatment has shown significant antidepressant-like effects in different rodent preclinical models.
However, the mechanisms involved in CBD-induced antidepressant effects are still poorly understood. Therefore, this work aimed at investigating the participation of serotonin (5-HT) and/or noradrenaline (NA) in CBD-induced antidepressant-like effects in the forced swimming test (FST) by: 1) testing if CBD co-administration with serotonergic (fluoxetine, FLX) or noradrenergic (desipramine, DES) antidepressants would have synergistic effects; and 2) investigating if 5-HT or NA depletion would impair CBD-induced behavioral effects.
Results showed that CBD (10 mg/kg), FLX (10 mg/kg) and DES (5 mg/kg) induced antidepressant-like effects in mice submitted to FST. Ineffective doses of CBD (7 mg/kg), when co-administered with ineffective doses of FLX (5 mg/kg) or DES (2.5 mg/kg) resulted in significant antidepressant-like effects, thus implicating synergistic and/or additive mechanisms.
Pretreatment with PCPA (an inhibitor of serotonin synthesis: 150 mg/kg, i.p., once per day for 4 days), but not DSP-4 (a noradrenergic neurotoxin: 1 μg/μl, i.c.v., 24 h before the test), reduced monoamine levels in the brain. However, only PCPA treatment abolished CBD-induced behavioral effects in FST, indicating the participation of serotonergic mechanisms. None of the treatments induced locomotor effects.
Our results suggest that the antidepressant-like effect induced by CBD in the FST is dependent on serotonin levels in the central nervous system (CNS).”
https://www.ncbi.nlm.nih.gov/pubmed/29885468
Sub-chronic treatment with cannabidiol but not with URB597 induced a mild antidepressant-like effect in diabetic rats.
“Depression associated with diabetes has been described as a highly debilitating comorbidity. Due to its complex and multifactorial mechanisms, the treatment of depression associated with diabetes represents a clinical challenge.
Cannabidiol (CBD), the non-psychotomimetic compound derived from Cannabis sativa, has been pointed out as a promising compound for the treatment of several psychiatric disorders.
Here, we evaluated the potential antidepressant-like effect of acute or sub-chronic treatment with CBD in diabetic rats using the modified forced swimming test (mFST).
Also, to better understand the functionality of the endocannabinoid system in diabetic animals we also evaluated the effect of URB597, a fatty acid amide hydrolase inhibitor.
Acute treatment with either CBD or URB induced an antidepressant-like effect in NGL rats, but not in DBT rats. However, sub-chronic treatment with CBD (only at a dose of 30 mg/kg), but not with URB597, induced a mild antidepressant-like effect in DBT animals. Neither body weight nor blood glucose levels were altered by treatments.
Considering the importance of the endocannabinoid system to the mechanism of action of many antidepressant drugs, the mild antidepressant-like effect of the sub-chronic treatment with CBD, but not with URB597 does not invalidate the importance of deepening the studies involving the endocannabinoid system particularly in DBT animals.”
https://www.ncbi.nlm.nih.gov/pubmed/29885450
“Currently available antidepressants have a substantial time lag to induce therapeutic response and a relatively low efficacy. The development of drugs that addresses these limitations is critical to improving public health.
Cannabidiol (CBD), a non-psychotomimetic component of 
“The nucleus accumbens (NAc) is a critical component of the reward circuitry, and dysfunction of the NAc may account for anhedonia and other symptoms of depression.
The endocannabinoid (eCB) system regulates mood, emotion, motivation, appetite, body weight, and cognition.
Here, we investigated whether alterations in endocannabinoid (eCB) signaling in the NAc contribute to depression-like behaviors induced by chronic unpredictable stress (CUS) in mice.
These results suggest that downregulation of eCB signaling in the NAc occurs after CUS and contributes to the pathophysiology of depression.”
“Chronic cannabis use is associated with neuroanatomical alterations in the hippocampus. While adverse impacts of cannabis use are generally attributed to Δ9-tetrahydrocannabinol, emerging naturalistic evidence suggests cannabidiol (CBD) is neuroprotective and may ameliorate brain harms associated with cannabis use, including protection from hippocampal volume loss. This study examined whether prolonged administration of CBD to regular cannabis users within the community could reverse or reduce the characteristic hippocampal harms associated with chronic cannabis use.
Results: No change was observed in left or right hippocampus as a whole. However, left subicular complex (parasubiculum, presubiculum, and subiculum) volume significantly increased from baseline to post-treatment (p=0.017 uncorrected) by 1.58% (Cohen’s d=0.63; 2.83% in parasubiculum). Heavy cannabis users demonstrated marked growth in the left subicular complex, predominantly within the presubiculum, and right cornu ammonis (CA)1 compared to lighter users. Associations between greater right subicular complex and total hippocampal volume and higher plasma CBD concentration were evident, particularly in heavy users.
Conclusions: Our findings suggest a restorative effect of CBD on the subicular and CA1 subfields in current cannabis users, especially those with greater lifetime exposure to cannabis. While replication is required in a larger, placebo-controlled trial, these findings support a protective role of CBD against brain structural harms conferred by chronic cannabis use. Furthermore, these outcomes suggest that CBD may be a useful adjunct in treatments for cannabis dependence and may be therapeutic for a range of clinical disorders characterized by hippocampal pathology (e.g., schizophrenia, Alzheimer’s disease, and major depressive disorder).”
“We examined the effects of essential oil from legal (THC <0.2% w/v) hemp variety on the nervous system in 5 healthy volunteers. GC/EIMS and GC/FID analysis of the EO showed that the main components were myrcene and β-caryophyllene.
The experiment consisted of measuring autonomic nervous system (ANS) parameters; evaluations of the mood state; and electroencephalography (EEG) recording before treatment, during treatment, and after hemp inhalation periods as compared with control conditions. The results revealed decreased diastolic blood pressure, increased heart rate, and significant increased skin temperature.
The subjects described themselves as more energetic, relaxed, and calm.
The analysis EEG showed a significant increase in the mean frequency of alpha (8-13 Hz) and significant decreased mean frequency and relative power of beta 2 (18,5-30 Hz) waves. Moreover, an increased power, relative power, and amplitude of theta (4-8 Hz) and alpha brain waves activities and an increment in the delta wave (0,5-4 Hz) power and relative power was recorded in the posterior region of the brain.
These results suggest that the brain wave activity and ANS are affected by the inhalation of the EO of