Correspondence

www.thelancet.com Vol 382 October 19, 2013 1325

Submissions should be made via our electronic submission system at http://ees.elsevier.com/thelancet/

used a whole-home approach to change cultural attitudes towards exercise in the homes to maximise residents’ physical activity outside the times of the exercise sessions. We had little eff ect on the homes’ overall approach to physical activity.1 Exercises were largely done seated because most of the participants were too frail to do standing exercise; for many of these individuals, seated exercises provided a moderate to hard challenge.

What we tested here is the type of intervention that, if eff ective, would be implementable across the care home sector. Our conclusion that the evidence does not support the use of this type of intervention to reduce the burden of depression in UK care home residents is extremely robust. This conclusion is supported by recent work in the fi eld.3 It is possible that exercise might be a useful treatment for fi tter old people with depression, including care home residents, who are able to achieve more intense levels of sustained physical activity.4 This is of little practical relevance to the population of interest. Alternative approaches are needed to reduce the burden of depression in this population. We declare that we have no confl icts of interest.

*Martin Underwood, Sallie Lamb, Bart Sheehan, David R Ellard, Stephanie J Taylor m.underwood@warwick.ac.uk

University of Warwick, Coventry CV4 7AL, UK (MU, SL, BS, DRE); and Queen Mary, University of London, Blizard Institute, Barts and The London School of Medicine and Dentistry, London, UK (SJT)

1 Underwood M, Lamb S, Eldridge S, et al. Exercise for depression in care home residents. A randomised controlled trial with cost-eff ectiveness analysis (OPERA). Health Technol Assess 2013; 17: 18.

2 Müller-Thomsen T, Arlt S, Mann U, Mass R, Ganzer S. Detecting depression in Alzheimer’s disease: evaluation of four diff erent scales. Arch Clin Neuropsychol 2005; 20: 271–76.

3 Koehler M, Rabinowitz T, Hirdes J, et al. Measuring depression in nursing home residents with the MDS and GDS: an observational psychometric study. BMC Geriatr 2005; 5: 1.

4 Underwood M, Lamb SE, Eldridge S, et al. Exercise for depression in elderly residents of care homes: a cluster-randomised controlled trial. Lancet 2013; 382: 41–49.

Exercise for depression in elderly peopleThe study by Martin Underwood and colleagues (July 6, p 41)1 shows that 1 year of exercise training had no effects on depressive symptoms among residents of care homes and nursing homes. Their results are probably robust, given the well-designed protocol and large sample size. However, two aspects need to be highlighted: the use of the Geriatric Depression Scale (GDS-15) as the measurement of depression and the participants’ low compliance regarding the exercise training.

Whilst the GDS-15 is a valid method for measuring depression in old adults, its use in care homes and nursing homes is questionable because of the high prevalence of dementia in these settings (almost 30% in Underwood and colleagues’ study1). Indeed, there is some evidence that the GDS-15 is not the most reliable method to assess depression in people with dementia,2 particularly in those with a mini-mental state examination (MMSE) less than 18 (mean MMSE was around 18 in Underwood and colleagues’ study). The high prevalence of undiagnosed dementia found in UK nursing homes3 would further increase the importance of this potential bias.

Another concern is the low com-pliance to the exercise training; only half of participants in the intervention group attended exercise sessions once a week. This weekly frequency is not suffi cient to provide the physiological benefits of exercise; this bias was probably increased by the fact that the exercises were largely done while seated, reducing the intensity of the exercises.

Therefore, while this study strongly contributes to the field of geriatric psychiatry, it is too early to affirm that exercise is ineffective to treat depressive symptoms in institutionalised old adults.

I declare that I have no confl icts of interest.

Philipe de Souto Barretophilipebarreto81@yahoo.com.br

Gérontopôle de Toulouse, Institut du Vieillissement, 31000 Toulouse, France

1 Underwood M, Lamb SE, Eldridge S, et al. Exercise for depression in elderly residents of care homes: a cluster-randomised controlled trial. Lancet 2013; 382: 41–49.

2 Müller-Thomsen T, Arlt S, Mann U, Mass R, Ganzer S. Detecting depression in Alzheimer’s disease: evaluation of four diff erent scales. Arch Clin Neuropsychol 2005; 20: 271–76.

3 Lithgow S, Jackson GA, Browne D. Estimating the prevalence of dementia: cognitive screening in Glasgow nursing homes. Int J Geriatr Psychiatry 2012; 27: 785–91.

Authors’ replyPhilipe de Souto Barreto raises two important points: first, was the Geriatric Depression Scale (GDS)-15 the most appropriate measure for this study? And second, was an adequate amount of exercise delivered?

For a large pragmatic trial, the GDS-15 is the most appropriate and practical primary outcome. The assessment is shorter than competing measures, it is usable by research staff without specialised training, it does not require carer interviews, it does not include somatic symptoms, and it has recognised measurement properties.1 While some reports have suggested lower internal consistency for GDS-15 in cognitively impaired care home residents, others suggest strong internal consistency and consistency with external measures of depression even in more cognitively impaired residents.2,3 In light of the results of the trial, in which we controlled for cognitive impairment, it would be extremely unlikely that the use of an alternative depression measure would have produced a diff erent result.

We agree that an adequate amount of exercise to achieve the physiological benefi ts of exercise was not achieved by some participants. This pragmatic trial was powered to detect small to medium eff ects and to account, therefore, for some non-compliance. Additionally, the exercise groups were just one component of the intervention. We

Hel

en K

ing/

Corb

is