Long-term Treatment Response in Bipolar Illness
Willem Nolen, a researcher who has spent 40 years studying unipolar and bipolar disorder, recently retired from his position at Groningen Hospital in the Netherlands. In February, his retirement was celebrated with a symposium where he and other researchers discussed some of their important findings from the last several decades.
Nolen recently published a double-blind randomized study showing that in patients who were initially responsive to monotherapy with quetiapine (Seroquel), continuing the drug (at doses of 300-800mg/night) or switching to lithium were both more effective than switching to placebo over 72 weeks of long-term follow-up.
This study shows that quetiapine, which is only FDA-approved for long-term preventative treatment when used in combination with lithium or valproate (Depakote), also has efficacy when used as monotherapy.
Lithium is Highly Effective in Long-term Prevention
Nolen’s work also adds to an impressive amount of literature showing that lithium is highly effective in long-term prevention. This case is especially noteworthy because lithium was effective even in patients who had initially been selected for their response to quetiapine. (Studies that use this kind of “enriched sample” can only claim that quetiapine has long-term efficacy in those patients who initially respond well to the drug.) The data on lithium are even more impressive since the patients in this study were not enriched for lithium response.
Nolen has also conducted multiple studies of lithium, but optimal doses and target blood levels of the drug remain controversial. The therapeutic range of lithium is usually considered to be 0.6 to 1.2 meq/L, but some have argued that lower levels may still be effective. In a new analysis of those patients in the quetiapine study who were switched to lithium treatment, Nolen found that only lithium levels above 0.6 meq/L produced better results than placebo in long-term prophylaxis. Read more