bipolar disorderLithium is the best drug to use to avoid hospital admissions for people with bipolar, a large study into the effectiveness of the drug has found.

Lithium has long been used by people with bipolar disorder and it is one of the main medications prescribed on the NHS for the illness. However, despite the National Institute for Health and Care Excellence advising in 2014 that lithium should be the standard treatment for bipolar disorder, its use has declined. One reason for this is that newer drugs have been marketed as alternatives by drug companies based on trials they have funded.

But these trials have been criticised for not being truly random – the drug each patient involved in the trial was carefully selected by a psychiatrist mindful of their “clinical features”, which in turn affects the outcome.

To get around this, researchers compared periods when individual patients were medicated with periods when they were not. The study was based on data from 35,022 people with bipolar disorder from Swedish national registers.

The study said: “The results will be notably free of any question of industry or allegiance bias and could improve confidence globally in the practice of psychiatry.”

Their findings back earlier studies, including those of a study last year into 4 drugs – lithium, valproate, olanzapine and quetiapine – which suggests lithium is the most effective drug in preventing relapse in people with bipolar disorder.

The study, led by Mikael Landen, from the Institute of Neuroscience and Physiology at Gothenburg University in Sweden, and involving Guy Goodwin, professor of psychiatry at the University of Oxford, said: “Our results provide strong evidence that lithium, valproate, lamotrigine, olanzapine and quetiapine lower the risk of psychiatric hospital admission in routine clinical practice.”

Professor Goodwin added: “This is a ground-breaking study for patients with bipolar disorder. It is highly reassuring to see that by persevering with lithium when well, patients can prevent admission to hospital with mania, depression or mixed states. Other treatments are simply not as effective when taken alone, although they may help to augment lithium’s effectiveness when taken together with it.”