If your depression is severe, I recommend that you start treatment with a conventional anti-depressant as opposed to St John’s Wort.
I would regard depression as being severe if it disrupts important functions, such as personal relationships or work to a major degree, if it is seriously interfering with physical functions such as sleeping or eating, or if it is accompanied by a sense of hopelessness or suicidal ideas or plans. To date, there has been only one study with St John’s Wort for relatively severe depression.
Although the results of that study revealed a beneficial effect of St John’s Wort equivalent to a modest dose of a conventional antidepressant, there are numerous studies indicating the value of more conventional anti-depressants in severe depression. At this point the benefits of St John’s Wort for severe depression must be considered somewhat experimental, and a more proven first-line approach makes more sense, given how much is at stake when depressive symptoms are severe. Severe depression can jeopardize a person’s job, relationship or the successful outcome of a project. Of even greater concern is the danger of suicide, which is a major risk of severe depression. A delay resulting from starting with a less well-established approach is therefore too risky. A doctor should be consulted and a trial of a conventional anti-depressant should be initiated without delay.
You are doing well, your depressive symptoms are under good control and side-effects are at an acceptably low level.
You are already being treated for depression but are not doing as well as you would like either because your depressive symptoms are not under control or because side-effects are unacceptable or undesirable.