Lack of evidence supporting use of antidepressants for insomnia

A rigorous review of research, led by the University of Southampton, has found there is not enough evidence to support the current clinical practice of prescribing antidepressants for insomnia.

Part-funded by the NIHR School for Primary Care Research, the review, published in the Cochrane Systematic Reviews Library, re-examined 23 previous studies involving a total of 2,806 patients with insomnia.

The researchers found that, overall, evidence supporting the use of antidepressants for people with sleep problems is of low quality – partly due to the small number of people in individual studies and partly due to how the studies were undertaken and reported.

Some low quality evidence was identified supporting short term (weeks, rather than months) use of some antidepressants, but no evidence was found for amitriptyline, which is commonly used in clinical practice. There was also no evidence to support long-term antidepressant use for insomnia.

Lead researcher, Associate Professor Hazel Everitt, says: “High quality trials of antidepressants for insomnia are needed to provide better evidence in this area to inform clinical practice. Additionally, health professionals and patients should be made aware of the current lack of evidence for antidepressant medications commonly used for insomnia management.”

Insomnia causes unsatisfactory sleep – both difficulty getting to sleep and staying asleep. It is a common problem, with one in five people reporting sleep problems each year. It can significantly impair quality of life, leading to physical or mental health problems and is associated with anxiety, depression and drug and alcohol abuse.

Management of the condition depends on its duration and nature. It may involve treating coexisting medical problems, providing advice on sleep habits and lifestyle, or using medicines and psychological therapies. Medicines called hypnotics are most commonly used to treat insomnia and are known to help, but can have problems, such as tolerance (needing to take more of the medicine to get the same effect) and dependence (physical or mental problems if the medicine is stopped). The use of antidepressant drugs to help with insomnia is widespread, but none are licensed for the condition and, as this study has shown, their effectiveness is unclear.

The review Antidepressants for insomnia in adults, which also involved the University of Cape Town, Bournemouth University, The Burden Centre at Frenchay Hospital and Imperial College, is published in the Cochrane Database of Systematic Reviews.

The review included past randomised controlled trials of adults with an insomnia diagnosis published in a selection of electronically available databases up to 2015.¹