Much of Edward Shorter's recent book, What psychiatry left out of the DSM-5: Historical mental disorders today, is, to my mind, speculative nonsense. However, there is a chapter on 'Bipolar craziness', which I think has some useful references. I've mentioned before (eg. see previous post) how the concept of bipolar spectrum has extended during my working lifetime to a notion whose meaning must be questioned. As Shorter says at the end of his chapter:-
Unlike in previous editions, when DSM- 5 was launched in 2013 the discussion of bipolar disorder was no longer merely a section of an "affective disorders" chapter but had a chapter of its own, as though the previous hundred years of world psychiatry had never existed.
Unipolar and bipolar disorders are now seen as separate disorders whereas they used to be seen as two subcategories of manic-depressive illness. I am not necessarily saying that the previous way of looking at this diagnostic issue was better, but it is clear that at least some of the motivation for the change has been to promote mood stabilisers for bipolar disorder (see eg. previous post).
It's suggested antidepressants should be avoided in treating patients with bipolar disorder in favour of mood stabilisers. However, I've also mentioned before that the risk of manic switch when using antidepressants has been exaggerated. NIMH has endorsed the use of the diagnosis bipolar disorder not otherwise specified to categorise bipolar disorder as on a spectrum (see press release). It affirmed that such patients were being inappropriately treated by giving antidepressants or other psychotropic medication in the absence of mood stabilisers. However, systematic reviews have not found evidence that switching to mania is a complication of antidepressant treatment (Gijsman et al 2004, Visser & Van Der Mast 2005). In a placebo-controlled trial, use of adjunctive, standard antidepressant medication, as compared with the use of mood stabilisers, was not associated with an increased risk of treatment-emergent affective switch (Sachs et al 2007). Moreover, there was no difference in efficacy.
The limitation of medication, whether antidepressants or mood stabilisers, needs to be recognised. Just because antidepressants are not always effective does not necessarily mean that even mood stabilisers will be helpful in so-called bipolar spectrum.