UK patients with bipolar disorder experiencing major depressive episodes can now be treated with AstraZeneca’s blockbuster antipsychotic Seroquel XL after the drug’s license was extended allowing its use for both poles of the disease.

The drug is already approved to treat manic episodes of bipolar disorder and with this licence extension has now become the only once daily atypical antipsychotic licensed in the UK to treat both poles of the condition, “thereby streamlining and simplifying therapy for patients and physicians”, according to the company.

The availability of Seroquel XL (quetiapine prolonged release) represents “a major advance” in therapy for bipolar depression, as in the absence of any therapy specifically approved for the condition doctors were using an ‘unlicensed’ mix of mood stabilisers and antidepressants, which can cause treatment emergent manic episodes and thus have a detrimental effect on the course of the illness, AstraZeneca said.

As Seroquel XL is associated with a relatively low incidence of treatment emergent mania - 4.4% in people taking 300mg versus 6.4% with placebo – experts hope that the drug will offer an effective and licensed alternative to antidepressant treatment for bipolar depression.