Cannabinoids and the endocannabinoid system in anxiety, depression, and dysregulation of emotion in humans.

PURPOSE OF REVIEW: This review is to summarize most recent evidence published in the last 18 months on medical and recreational use of cannabis and cannabinoids in relation to anxiety, depression (unipolar and bipolar), and dysregulation of emotions as part of posttraumatic stress disorders (PTSD) and emotionally instable personality disorders. It also covers the investigation of endocannabinoids as potential biomarkers in these conditions. This is important with increasing medicinal use of cannabinoids and growing social tolerance towards recreational cannabis use. RECENT FINDINGS: There is some recent evidence suggesting cannabinoids, cannabidiol or cannabidiol-enriched cannabis preparations have anxiolytic properties. In addition, depression may be worsened by cannabis use, however, randomized controlled trials (RCT) are lacking. New evidence also suggests that cannabidiol or cannabidiol-enriched cannabis use for PTSD and emotion regulation can induce hyporesponse to fear and stress. Further, several lines of evidence point to the endocannabinoid system as a key player in some of the reviewed disorders, in particular anxiety and PTSD. SUMMARY: The most recent evidence for a therapeutic use of cannabinoids in the reviewed conditions is weak and lacking well designed RCTs. However, there is some indication of the role of the endocannabinoid system in these conditions that warrant further studies.

Role of the Endocannabinoid System in the Pathophysiology of Schizophrenia: Implications for Pharmacological Intervention.

The term schizophrenia describes a group of multifaceted psychiatric conditions causing significant impairment of the quality of life of affected patients. Although multiple pharmacological treatment options exist, e.g. first- or second-generation antipsychotics, these therapeutics often cause disturbing side effects, such as extrapyramidal symptoms, prolactin increase, sexual dysfunction and/or metabolic syndrome. Furthermore, cognitive impairments and negative symptoms, two factors significantly influencing the course and outcome, are not sufficiently addressed by the available antipsychotics. Since its discovery, multiple clinical and preclinical studies have linked the endocannabinoid system to schizophrenia. Both the endocannabinoid anandamide and the cannabinoid CB1 receptor are deeply linked to underlying disease processes. Based hereon, clinical trials in schizophrenia have explored cannabidiol, a primary component of Cannabis sativa, and rimonabant, a partial antagonist to the CB1 receptor. While the latter did not reveal positive results, cannabidiol significantly ameliorated psychotic symptoms, which was associated with an increase in anandamide serum levels. However, the exact mechanisms of the antipsychotic effects of cannabidiol are not fully understood, and, furthermore, only a limited number of clinical trials in humans have been concluded to date. Thus, the level of proof of safety and efficacy required to approve the therapeutic use of cannabidiol in schizophrenia is currently lacking. However, cannabidiol is a promising candidate as an effective and mechanistically different antipsychotic treatment with a favourable side-effect profile. We therefore conclude that further studies are urgently needed to clarify the antipsychotic effects and safety profile of cannabidiol, and to fully explore its potential antipsychotic mechanism.

Ziprasidone versus clozapine in the treatment of dually diagnosed (DD) patients with schizophrenia and cannabis use disorders: a randomized study.

BACKGROUND AND OBJECTIVES: Clozapine is considered to be particularly effective in the treatment of dually diagnosed (DD) patients with psychosis and substance use disorders. However, its use is restricted by potentially severe side effects. The aim of the present pilot study was to compare the effects of clozapine with the newer second generation antipsychotic (SGA) ziprasidone in DD-patients. METHODS: Thirty (n = 30) patients with schizophrenia and cannabis abuse/dependence were randomized to ziprasidone or clozapine and were followed up for up to 12 months. RESULTS: Cannabis use was reduced in both groups during follow-up. Clozapine treatment was associated with less positive symptoms of schizophrenia, more side effects and poorer compliance with treatment. CONCLUSIONS: Results from this small pilot RCT suggest beneficial effects of both clozapine and ziprasidone in the treatment of cannabis use disorders in psychotic patients. Larger-scale RCTs are needed in order to assess advantages and disadvantages of the different SGAs in dually diagnosed populations.