Patients with bipolar disorder have the lowest risk of re-admission to hospital if treated with lithium, according to Swedish researchers, who said it should remain the “first line treatment”.
Long-acting injections of antipsychotics were also effective, reducing the risk of rehospitalisation by 30% compared with their oral counterparts, said the researchers from the Karolinska Institutet.
“Our results show that lithium should remain the first line of treatment for patients with bipolar disorder”
They noted that lithium was considered to be the most effective mood stabiliser, but only a few studies had been conducted comparing the long-term effects of different drugs in bipolar disorder.
They compared the risk of re-admission to hospital in more than 18,000 patients in Finland who had previously been hospitalised for bipolar disorder. Each patient was used as their own control, being compared during periods with and without treatment.
During an average follow-up time of more than seven years, lithium treatment was associated with the lowest risk of re-admission in mental or physical disease, with a risk reduction of about 30% compared with no treatment at all.
Long-acting injections of antipsychotic drugs were also effective. The risk of re-admission was around 30% lower if patients were treated with long-acting injections compared to their receiving the same antipsychotic medication but orally.
However, the most commonly prescribed antipsychotic for bipolar disorder, quetiapine (Seroquel), which is given in tablet form, showed only “modest effectiveness” and reduced the risk by just 7%.
“Lithium was the most effective mood stabilizer, and long-acting injections the most effective antipsychotics, in preventing hospitalization due to mental or physical illness,” said the authors in the journal JAMA Psychiatry.
Senior study author Professor Jari Tiihonen said: “The prescription of lithium has decreased steadily in recent years, but our results show that lithium should remain the first line of treatment for patients with bipolar disorder.
“Long-acting injections might offer a safe, effective option for patients for whom lithium is not suitable,” he added.
The research was funded by the Finnish Ministry of Social Affairs and Health with no pharmaceutical company finance involved, noted the authors.