The markedly broadened criteria for the diagnosis of bipolar disorder since 1980’s led to a significant heterogeneity. IGSLI continues working on the hypothesis that the identification of major bipolar subtypes distinctly improves the response in patients on long-term treatment. IGSLI has been also actively involved in identifying patients for whom lithium is the maintenance of choice.
The findings show that the patients who respond best to lithium are those who demonstrate the classic manic-depressive profile. These patients show an episodic course of illness, family history of bipolar disorder and lithium responsiveness, full remissions inbetween episodes, and lack of mood incongruent psychotic features (Grof et al. 1992).
On the other hand, atypical features clearly reduce the quality of response to stabilizing lithium (Berghoefer et al 2006, Pfennig et al 2010). In a long-term study of 336 patients with bipolar I and II disorders, treated with lithium for up to 30 years, the risk of recurrence was negatively influenced by the presence of atypical features. According to these findings, lithium is less effective in patients with other subtypes of bipolar disorder presenting with mood-incongruent psychotic features, substance abuse, anxiety disorders or other psychiatric comorbidity, and by residual symptoms between episodes. Results from several other European research groups support this hypothesis.
Distinguishing between subtypes may also be useful for evaluating the prognosis of bipolar women during pregnancy. In a retrospective study, the IGSLI showed that, in women with classical bipolar disorder, the risk of recurrence during pregnancy was markedly lower than had been expected in light of the usual clinical course. Exploring the underlying protective mechanisms in such cases may help lead to a new understanding of the pathophysiology of affective disorders and to new approaches to treatment and prevention.
The spectrum of therapeutic options has broadened since the emergence of anticonvulsants as a means of treating affective disorders. Applying lithium and anticonvulsants in a more differential manner might bring considerable benefits, especially to the large number of patients whose illness differs significantly from the classical type of bipolar disorder and who belong to the bipolar spectrum. Nevertheless, recently released overviews underscore the fact that lithium is still the first-line treatment in the prophylaxis of bipolar affective disorder.
The issue of anti-suicidal effect of lithium is covered under a separate heading.