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Preliminary study examines effects of 'cognitive enhancement' drug on sleep-deprived doctors

Preliminary study examines effects of 'cognitive enhancement' drug on sleep-deprived doctors

Modafinil improves performance in mental tasks but has no effect on surgical motor skills in small new study - News Release

Imperial College London News Release
For immediate release
Friday 14 October 2011

Researchers have carried out a preliminary study looking at the effects of the 'cognitive enhancement' drug modafinil on the performance of doctors who had been deprived of sleep for one night.

Modafinil, discovered in the 1970s, is currently prescribed in the UK for the treatment of sleepiness associated with narcolepsy, sleep apnoea, and shift work sleep disorder, a condition that affects people who frequently have to work at night.

In the new study of 39 people, published today in the Annals of Surgery by researchers from Imperial College London and the University of Cambridge, modafinil improved performance in a series of mental tasks when compared with placebo, but had no effect on the performance of a surgical motor skills task. The doctors did not interact with any patients during the exercise.

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Long periods without sleep are known to increase doctors' risk of making poor judgements and committing medical errors. The study was designed as a preliminary investigation into whether certain drugs might be effective at reversing some of the effects of fatigue.

Colin Sugden, Clinical Lecturer in Surgery, Department of Surgery and Cancer at Imperial College London, who led the study, said: "This study set out to explore whether modafinil, a wakefulness-promoting drug, might help doctors to perform more effectively under conditions of fatigue when their performance might otherwise be compromised."

In this randomised double-blind trial, 20 healthy male doctors took modafinil and 19 took a placebo after one night of sleep deprivation. All were asked to complete both a series of tasks that are commonly used in psychology research and a virtual reality surgical motor skills task.

In the psychological tasks, the group that had taken modafinil performed better in tests of working memory and planning, were less impulsive decision-makers, and were more responsive to changing demands during a task. However, there was no significant difference between the two groups on the surgical motor skills task.

Mr Sugden said: "Participants in the modafinil group were less impulsive, displayed greater flexibility and solved working memory and planning problems more efficiently than those in the placebo group. However, no benefit was seen in the performance of a basic motor skills task. This was a small, short-term study so we have to be very cautious about how the results are interpreted. Most importantly, it is not clear how performance on tests of mental function relate to how someone performs as a doctor."

The researchers stress that these results remain to be confirmed with a larger sample size and ideally in a longer term study.

The research explored the effects of one dose of modafinil over a short term and it was not designed to investigate the effects of repeated use, either on a person's physical and mental health or on their performance.

Mr Sugden said: "Larger studies looking at the performance effects and safety of longer term use of the drug would need to be performed before we could draw conclusions about whether or not sleep-deprived doctors might benefit from taking it. There are also many challenging ethical considerations which will need to be thought through very carefully.

"We should continue to do everything we can to ensure that doctors aren't in a situation where fatigue might impact upon their performance. We don't suggest that anyone should take modafinil to combat sleep deprivation, unless it has been prescribed by a doctor.

The study was funded by Imperial College London.


For further information please contact:

Sam Wong
Research Media Officer
Imperial College London
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Notes to editors:

1. Journal reference: C. Sugden et al. 'Effect of pharmacological enhancement on the cognitive and clinical psychomotor performance of sleep deprived doctors.' Annals of Surgery, 2011 DOI: 10.1097/SLA.0b013e3182306c99

2. About Imperial College London

Consistently rated amongst the world's best universities, Imperial College London is a science-based institution with a reputation for excellence in teaching and research that attracts 14,000 students and 6,000 staff of the highest international quality. Innovative research at the College explores the interface between science, medicine, engineering and business, delivering practical solutions that improve quality of life and the environment - underpinned by a dynamic enterprise culture.

Since its foundation in 1907, Imperial's contributions to society have included the discovery of penicillin, the development of holography and the foundations of fibre optics. This commitment to the application of research for the benefit of all continues today, with current focuses including interdisciplinary collaborations to improve global health, tackle climate change, develop sustainable sources of energy and address security challenges.

In 2007, Imperial College London and Imperial College Healthcare NHS Trust formed the UK's first Academic Health Science Centre. This unique partnership aims to improve the quality of life of patients and populations by taking new discoveries and translating them into new therapies as quickly as possible. Website:

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