Wendy - Doh! Sorry about the <A target="_blank" HREF=http://www.mentalhealth.com/book/p40-sad.html#Head_9>light therapy</A>, I guess that "http://http://" doen't work very well.
The main thing to watch for when one has taken an overdose of of St. Johns Wort is something called "serotonin syndrome" which is fairly rare, but I have seen cases of serotonin syndrome once when SJW was taken with Manerix™ (moclobemide) and have dealt with several cases where SJW was taken concomiitantly with various SSRIs, and a couple cases where it was combined with amitryptyline.
I have been involved with only one case where I thought that the serotonin syndrome was bad enough for me to consider it life-threatening. This was a case of a deliberate suicide attempt in a doctor's office, and I just happened to be there at the time.
Serotonin syndrome is defined as, "potentially dangerous oversupply of serotonin in the body, have been attributed to taking St. Johnís wort. Uncontrolled serotonin syndrome may result in coma, seizures, and death. Symptoms of serotonin syndrome include: confusion, euphoria, fever, hallucinations, inability to coordinate muscles, nausea restlessness, shakiness sweating, and vomiting. A good review of serotonin syndrome can be found on the website of the journal, <A target="_blank" HREF=http://www.currentpsychiatry.com/2003_05/0503_serotonin.asp>Current Psychiatry</A>
Other
and <A target="_blank" HREF=http://www.drugdigest.org/DD/DVH/HerbsInteractions/0,3926,4049|St.+Johns+Wort,00.html>drug interactions, as well as
are included on the enclosed website links. Also, on the same website, the webmasters have included <A target="_blank" HREF=http://www.drugdigest.org/DD/DVH/HerbsWho/0,3923,4049|St.+Johns+Wort,00.html>who should take SJW and <A target="_blank" HREF=http://www.drugdigest.org/DD/DVH/HerbsTake/0,3927,4049|St.+Johns+Wort,00.html>if you want to know if SJW is for you</A>.
SJW is not recommended for severe depression, as it has been shown only to definitively treat mild/moderate depression. Even proponents say that SJW does not work well in severe depression. This is probably due to the fact that as you increase the dose of SJW to amounts that would be effective in severe depression, the side effects of other chemicals in the plant become too pronounced.
SJW is not recommended in bipolar disorder for the same reasons that other serotonergic antidepressants are not recommended. There is a similar risk of developing hypomania from SJW as is seen with SSRIs.
If your depressive symptoms return when you go off SJW, you may still need to take it to stay in remission from depression. There is no need to take SJW year round if you are only having seasonal problems with depression.
If you are fairly certain that your depression is seasonal, the adverse effects that you are experiencing could potentially be serotonergic withdrawl symptoms. This is strictly a guess; I am thinking out loud right now. I have never seen <A target="_blank" HREF=http://www.preskorn.com/books/omd_s6.html>Serotonin Withdrawl Syndrome</A> (see the bottom of the page for SWS) with SJW, but theoretically it could happen.
I hope that this hlps somewhat - Cam