More research data on St John’s wort’s mechanism of action

April 14, 2010 Posted in: Alternative Treatments, Anxiety Disorders, Depression, OCD Tags: St John's wort 1 Comment

A lot has been written on St John’s wort and its efficacy in Depression and Anxiety Disorders. Hypericum perforatum L. (usually referred to as St. John’s wort) extracts have gained popularity as an alternative to conventional antidepressant drugs for mild to moderate forms of depressive disorders.

On the basis of animal studies, this article reviews new potential psychiatric uses for extracts of St. John’s wort in obsessive-compulsive disorder (OCD), generalised anxiety disorder and alcohol dependence have also been suggested .

Although the true mechanism of action (at a neurobiological level) is still somewhat debated, several components have antidepressant-like and anxiolytic-like effects in animals, or interact with neurotransmitter systems believed to be causally involved in depression, anxiety and in psychiatric illness generally.

The article goes on to review the evidence about the pharmacokinetics of St. John’s wort (that is, the mechanisms of absorption and distribution of the substance once it is administered), particularly those of their brain distribution and concentrations and the relationships with blood concentrations. According to the authors, the brain concentrations of the active compounds of St. John’s wort are below those effective on neurotransmitter receptors (even after pharmacologically effective doses of the extracts).

Now, how should we interpret this? Well, the authors point our the need for more studies that provide additional pharmacokinetic data on the brain concentrations of St. John’s wort for a more meaningful interpretation its effects on the brain.

The advancement of science is, regrettably, slower than we would like it to be. That means that questions such as “Is St. John’s wort a good treatment for Depression or for Anxiety Disorders?” cannot be fully answered with the data at hand. Therefore, the clinician has to use his/her judgement to carefully consider the options in each case.

In my clinical practice I have sometimes prescribed John’s wort extracts, and the results have been mixed: some clients improved significantly, while others did not report a significant improvement in their condition. For me, a key issue is the client’s attitude towards conventional medication and alternative treatments. When a client has failed to improve on psychotherapy but is reluctant to take conventional treatments (such as antidepressants), sometimes alternative treatments (including John’s wort) are valid options to consider, especially when the client is keen on them.

The original article is Open source and can be accessed for free here.