Improving Sleep Continuity Through Mindfulness Training for Better Cognitive Ageing.

Poor sleep quality is a known risk factor for cognitive decline in the elderly. Hearteningly, sleep is also a prime target for behavioral modification. In this study, the investigators propose to test mindfulness-based training (MBT) as an intervention to improve sleep quality by reducing sleep fragmentation, and hypothesize that these improvements will mediate the beneficial effects of MBT on sustained and executive attention. MBT consists of a suite of techniques aimed at enhancing awareness and acceptance of one's internal (e.g., thoughts and feelings) and external experiences in the present moment. Learning these techniques has been shown to improve sleep quality in patients with primary insomnia, and in other conditions associated with sleep disturbance. There is also increasing evidence that mindfulness training enhances multiple facets of cognition, including components of attention. In this study, the investigators will recruit 120 participants in a randomized controlled design, with 60 participants receiving MBT, and 60 receiving a sleep hygiene education and exercise program (SHEEP). Each intervention will last 8 weeks. Before and after the intervention, the investigators will collect objective and subjective measures of sleep quality, resting-state and task-related functional magnetic resonance imaging scans, and performance on standard laboratory tests of attention. The investigators hypothesize that, relative to SHE, MBT will result in significantly greater improvements in sleep quality and attentional metrics. They also predict that the cognitive changes will be mediated by the changes in sleep quality. If a positive result is found, this would indicate the use of MBT as a cost-effective behavioral intervention to stabilize or even improve cognition in the elderly, thus reducing the risk of dementia in this vulnerable population.

Cognitive decline in the elderly is a rapidly growing concern in Singapore and other developed Asian nations. Among the major but understudied factors that may exacerbate this decline is poor sleep quality. Targeting sleep to decelerate or even reverse age-related cognitive decline may represent a low-cost, high-return solution to a widespread societal problem.

To accomplish this goal, the investigators propose to test mindfulness-based training (MBT) as an intervention to improve sleep quality and cognition.

In this pilot grant, the investigators will study a group of participants (N = 120) in a randomized controlled design pitting MBT (N =60) against sleep hygiene education (SHEEP, N = 60).

Hypothesis 1: MBT will lead to significantly greater improvements in sustained and executive attention relative to SHEEP (measured both behaviorally and using functional magnetic resonance imaging).

Hypothesis 2: Cognitive outcomes will be mediated by improvements in subjective and objective sleep quality.

Good sleep is critical for cognition at all ages, and especially in the elderly

Adequate sleep is important for optimal cognitive function across the lifespan. Although the association between sleep and cognitive function is bi-directional, alterations in sleep frequently occur prior to the appearance of cognitive symptoms in Alzheimer's Disease (AD). Almost 50% of older adults report at least one sleep problem, and there is growing evidence that sleep complaints and disturbances might have negative effects on cognition.

Retired older adults have the freedom to sleep ad libitum but this benefit is offset by age-associated changes in sleep such as poorer subjective quality, increased fragmentation and/or altered macrostructure. Although sleep duration is the measure that has received the most attention, there is accumulating evidence that sleep quality (Blackwell et al., 2014) and sleep fragmentation in particular, can have deleterious effects on brain structure and cognition. A change in sleep pattern in late adulthood can foreshadow cognitive decline, perhaps as a result of accumulation of neurotoxic substances that are normally cleared during sleep.

Eligibility Criteria:
Inclusion Criteria:

1. Adults aged 50 to 80
2. English-speaking
3. Mini-Mental State Examination Score ≥ 26
4. Montreal Cognitive Assessment Score ≥ 23

At least one of the following sleep difficulties are expressed:

(i) average reported sleep latency of more than 30 minutes

(ii) average wakefulness after sleep onset of more than 30 minutes

(iii) sleep efficiency or total sleep time of less than 6.5 hours

and/or

(iv) also a cut off in the PSQI\>/=5

Exclusion Criteria:

1. Presence of major neurological conditions such as epilepsy, stroke, Parkinson's Disease and/or brain injury
2. Presence of major psychiatric conditions such as major depression or schizophrenia
3. Unsuitability for fMRI scanning (e.g. pacemakers, metallic implants, claustrophobia)
4. Unable to give independent consent or no consent available