So when you give a bipolar too potent, too lengthy, and/or too frequent an antidepressant, you just might cause the depression to end in a mania and, perhaps, some time later, a more severe depression than usual. (Frye, Ketter 2001, Post 2003, Brigham 2001) In fact, psychiatrists have become a lot more cautious about giving antidepressants to bipolars.
Similar concerns are beginning to surface around the antipsychotic meds used for mania and psychotic depression. (Whybrow 1997, Brigham 2001)
So that mainstream psychiatry has given voice to the advisability, where possible, of weaning antidepressants and antipsychotics around the time that the corresponding episode resolves. (Unfortunately, when such meds are stopped, especially if done abruptly, rebounds can be disastrous.)
In the same manner, street drugs, trauma, psychosocial stress, even seasonal change and junk-food diets, can trigger episodes.
And as a general rule, with each additional episode, the illness becomes increasingly difficult to treat. (Masters 1996, Goldberg 1999)
New episodes are rarely triggered by nutrients, although potent, rapidly-acting, symptomatic nutrients can do so (e.g., SAMe, mistakenly given to people prone to brain overmethylation).
So when symptomatic treatment is required (e.g., to stop a depression), the ideal goal might be the mildest treatment strong enough to achieve the desired degree of response.
As the focus of treatment moves toward underlying causes this yo-yo effect phases out.
I like the vision of health care put forth by Hyla Cass, MD, on her website:
For further discussion, and for sources, see my book, Natural Healing for Bipolar Disorder