I believe there was one case written up in an Oliver Sacks book where an older woman became really really happy, to the point that her friends asked her to get it checked out. It turns out that she had an advanced case of syphilus that was beginning attack her brain. The good news is that they could stop the syphilus pretty easily, but the bad (well…also good) new is that the damage to her brain that was making her so happy was permanent.
I should have been more specific - the efficacy for both treatments is around 67% for patients with mild to moderate depression. Those with severe depression are much more difficult to treat and thus efficacy rates are lower.
I do have a recent text book at home that says these numbers specifically, however it’s home and I’m not so I’ll have a hard time citing it right now.
Manic/depressive symptoms are common among people with bipolar disorder. Many patients choose to NOT take their meds. in order to experience the “high” knowing full well the severity of the depression that is to follow.
Since it is nearly impossible to do double-blind studies of behavioral therapy, it is not easy to make scientific statements about it.
Here is one of many studies that show therapy to be less effective than medication (also known as pharmacotherapy cite): “This report compares response to cognitive-behavioral therapy (CBT) and pharmacotherapy…depressed men treated with pharmacotherapy had significantly greater improvements…and a significantly lower rate of nonresponse (i.e., 13% vs. 46%)”
Thase ME, et al, J Clin Psychiatry. 2000
In a study with double-blind controls, “Imipramine plus CBT is significantly more efficacious than placebo plus CBT in improving school attendance and decreasing symptoms of depression in school-refusing adolescents with comorbid anxiety and depression.” (cite).
Furthermore, there is doubt about whether psychotherapy is effective for some kinds of depressive states (cite), “…there is not yet compelling evidence that melancholic patients respond to psychotherapy as well as they do to medications.” This is probably also true for some people in manic states.
There are plenty of ideas about the physiology of mood that have nothing (or little) to do with serotonin. From the same study as above “The potentially mediating effects of hypercortisolism, alterations of sleep neurophysiology, and disturbances of information processing and regional cerebral metabolism represent fertile grounds for future investigation.”
Mahfuz, Najib. “The Happy Man.” In In God’s World: An Anthology of Short Stories. Translated by Akef Abadir and Roger Allen. Minneapolis: Bibliotheca Islamica, 1973, p. 19-29.