The investigation also found conversations with patients often focused on the risks of lithium before its benefits, deterring patients from the treatment.

Matthew Mansbridge, senior safety Investigator at HSSIB, said: ‘Lithium can transform the lives of people with bipolar disorder, and national guidance is clear that it should be considered early. What we found is that the systems around lithium are not giving clinicians the confidence to offer it. Prescribers are carrying responsibility for monitoring largely on their own, and there is no national picture of whether this is happening as it should. Better national oversight and a clear protocol would help clinicians and patients feel confident that lithium can be used safely.'

Despite being the most effective, long-term treatment for bipolar disorder, one study found that lithium prescribing had fallen from 30% in 2001 to around 16% in 2018. Clinicians told HSSIB that second-generation antipsychotics such as quetiapine and olanzapine were often considered first because they were seen as ‘just as good' and carrying fewer risks, however, this view is not supported by national guidance or the evidence.

HSSIB recommended the Royal College of Psychiatrists set out a clear national position on lithium, with a protocol covering expectations on monitoring, local oversight and assurance.

HSSIB also urged NHS England and the DHSC to develop national oversight and assurance processes to understand and improve how lithium treatment is managed across care settings.

Professor Subodh Dave, president of the Royal College of Psychiatrists, said: ‘The College is committed to developing a national position statement, to help clinicians offer evidence-based treatment and ensure people with bipolar disorder receive the high-quality care they need and deserve.

‘I have also appointed a presidential lead for clinical effectiveness to help ensure that effective treatments, such as lithium, are used consistently across services. We are producing through a collaborative, established by the College and Bipolar UK, a broader position statement on bipolar disorder, which we hope will provide the opportunity alongside the lithium work to help drive progress for this important group of patients.'