About the Study

Find out more about the APPLE-Tree Study


Observational studies indicate that approximately a third of dementia cases are attributable to modifiable physical and mental health, and social and lifestyle risk factors. There is evidence that behaviour change interventions targeting these factors can reduce cognitive decline. We have designed and will now be testing a low intensity, secondary dementia-prevention programme to slow cognitive decline in people with subjective cognitive decline with or without objective cognitive impairment. This intervention will be delivered online over Zoom whilst restrictions related to Covid-19 are in place.

Study aims

Phase 1: To test whether the APPLE-Tree intervention is acceptable and feasible to deliver in practice, and explore how we might increase acceptability and feasibility by adapting the intervention before phase 2.

Phase 2:

Primary: To conduct a randomised controlled trial to evaluate the clinical effectiveness (in terms of reducing cognitive decline) of the APPLE-Tree intervention in individuals at high risk of dementia with mild cognitive impairment (MCI) or subjective cognitive decline (SCD) at 24-month follow-up.

Secondary: To evaluate the cost-effectiveness of the APPLE-Tree intervention in individuals with MCI or SCD at 24-month follow-up.

Process evaluation: To explore how the intervention was implemented (to include fidelity, dose and reach) and any mechanisms of impact which produce behavioural and lifestyle changes during and beyond the facilitated sessions investigate.

Phase 3 (Implementation):

To explore what factors may determine decisions of NHS and third sector organisations who are not taking part in the trial, regarding whether they decide to adopt the new intervention, if it is demonstrated to be clinically effective and cost-effective.

What will happen in the study?

For those who agree to take part in this study, they will be invited to talk to a researcher over Zoom. This call will take around 1 hour and a half, during which the participant will complete questionnaires with the researcher, including a memory test and give a voluntary blood sample. We will also talk to a relative/friend who will act as a 'study partner' for the participant. We will provide the appropriate technology to participants without a device so that they can use Zoom.

After this, the researcher will contact participants again to tell them if they have been randomly allocated to receive the new APPLE-Tree programme or to receive written information about dementia prevention and information for services only.

The researcher will meet participants again at 12 months and 24 months to repeat the assessments, including the blood test if they agree to this. We may also invite some participants to take part in a separate, qualitative interview if they received the new programme, to learn about their experience of the sessions and get feedback

APPLE-Tree intervention

We will invite participants allocated to receive the new APPLE-Tree programme to attend ten group sessions over a 5-month period over Zoom. We will offer individual sessions for people who cannot come to groups. Two facilitators will lead the groups.

Our programme will help older people make changes that can prevent dementia. These are:

  1. Being more socially and mentally active
  2. Eating more healthily
  3. Being more physically active
  4. Looking after their mental and physical health
  5. Stopping smoking
  6. Reducing alcohol


We are looking for people who:

  • Are aged 60+
  • Are concerned about their memory
  • Don’t have dementia
  • Have a relative, friend or professional in at least monthly contact who is able and willing to act as the study partner

The study is taking place at sites within two hours of London or Essex. To find out more, please email us on dop.apple-tree@ucl.ac.uk