The finding: This is a review article summarizing studies of oral ketamine for the treatment of depression or for the treatment of pain. The authors found that in comparison to studies of oral ketamine for the treatment of pain, the studies of oral ketamine for the treatment of depression tended to be of shorter duration. While oral ketamine seems to be well tolerated in the short-term, few studies have looked at longer-term outcomes.

Strength and weaknesses: While the authors describe a thorough search strategy, they did not report employing a full systematic review methodology. They used creative strategies to synthesize the data and present them visually in a reader-friendly way.

Relevance: Many studies have looked at using intravenous ketamine for the treatment of depression and for the treatment of pain. The authors address the gap in the literature on oral ketamine by conducting a review of studies on oral ketamine for the treatment of depression and for the treatment of pain. Whether for the treatment of pain or depression, the gaps in the literature on the use of oral ketamine were highlighted at length in this article. Though only mentioned briefly, the authors note that oral ketamine may have a role in the treatment of comorbid pain and depression. Given how challenging it can be to treat comorbid pain and depression, this may be viewed as the most important gap identified in the literature and perhaps the most intriguing one for C-L psychiatrists. Future studies will have to evaluate the efficacy and tolerability of oral ketamine for this purpose before its use can be recommended for this purpose.

The finding: Over a 7-month average follow-up period, patients with chronic pain who were treated with cannabis showed improvements in pain and quality-of-life rating scales. A significant percentage of patients discontinued opiate use during the study period. Cannabis was relatively well tolerated.

Strength and weaknesses: The main strength is the large sample size and long follow-up period, since many studies of cannabis have been in small samples and over short treatment periods. A major limitation of the study is that it was open-label and lacked a control group. Also, the fact that there were relatively low prevalence rates for comorbid pain and psychiatric illness call into question whether a sampling bias exists, and whether or not the results are generalizable.

Relevance: This study adds to the growing body of literature on cannabis for the treatment of chronic pain, and bolsters the mounting evidence that pain specialists may have an additional tool at their disposal. More studies are needed to clarify the efficacy, safety, and tolerability of cannabis for patients with comorbid pain and psychiatric illness before C-L psychiatrists start prescribing cannabis routinely in this patient population.

The finding: This is a thorough review of the clinical, research and policy issues that are related to herbal cannabis.

Strength and weaknesses: The article focuses on cannabis as it relates to its use in pain disorders, but many of the principles can be generalized to the non-pain psychiatric setting.

Relevance: Cannabis for medical uses is increasingly available in many US states and in all Canadian provinces. Whether prescribing cannabis or not, C-L psychiatrists may be called upon to counsel their patients, and they will need to be well-informed.