A new study concludes that taking the drug modafinil, typically used to treat sleep disorders, in combination with antidepressants reduces the severity of depression more effectively than taking antidepressants alone.

Approximately a third of depressed patients receive little or no benefit from taking antidepressants. Those who do respond to treatment can suffer residual symptoms such as fatigue and trouble sleeping, which put them at risk of relapse. The study suggests these patients in particular would benefit from supplementing their antidepressants with modafinil.

Professor Barbara Sahakian, Department of Psychiatry, says: “Modafinil has actions on a number of neurotransmitter systems. This may explain why adding it to traditional anti-depressants, such as selective serotonin reuptake inhibitors, has beneficial effects on the symptoms experienced by depressed patients.”

The study revealed that modafinil reduced the severity of depression and improved remission rates. The benefits of the drug may also improve a patient’s ability to function at work, potentially reducing absenteeism.

The study, a collaboration between the Universities of Cambridge and East London and King’s College London, is published in the Journal of Clinical Psychiatry, and can be accessed here.