Another important factor influencing health and wellbeing of people living with chronic conditions is sleep. Many chronic conditions are associated with sleep-related problems, including sleep-related breathing disorders, insomnia, sleep-related movement disorders and sleep-related epilepsy \citep{Basnet2016,Dyken2012}. Critically, sleep quality is vitally important for people living with chronic conditions as it can worsen their already existing symptoms, for example, sleep quality has been shown to impact on metabolic function of type 2 diabetes \citep{Lee2012}. More generally, comorbid insomnia with a chronic condition is more severe and persistent than in cases where insomnia is the only disorder \citep*{Ancoli-Israel2006}. Among an elderly population with comorbid medical and mental illness, sleep is a useful predictor for general physical and mental health-related quality of life status \citep{Reid2006}. Sleep – in both the general population and among people with chronic conditions – can be improved through physical activity \citep{Hartescu2015,Kredlow2015}. Alternative forms of exercise such as Tai Chi are now being adopted and researched to encourage greater physical activity \citep{Raman2013}. Other methods through which sleep can be improved include music therapy, with research highlighting benefits for both acute and chronic sleep disorders \citep*{Wang2014}. Massage, acupuncture, natural sounds and music videos have also been reported to be effective in health care settings \citep*{Hellström2011}. Environmental modifications may also be another option for improving sleep, especially for those living in care homes, and this opportunity is discussed further within the section on the environment below.
In addition to positive health behaviours, the promotion of individual strengths such as acceptance, optimism and resilience are likely to promote health and wellbeing in people living with chronic conditions. These strengths are developed through cognitive-behaviour therapy, acceptance and commitment therapy and positive psychotherapy \citep{Hughes2017,Joyce2018} (Neenan, 2011). Understandably, people living with chronic conditions have a much lower level of resilience compared to healthy individuals although notably, increased resilience among those living with a chronic condition is associated with reduced psychological distress, and reduced symptoms of anxiety and depression [REF]. Strikingly, a strong sense of coherence (or SOC) is associated with a 30% reduction in mortality rate from cardiovascular disease, cancer and all cause-related death [REF]. SOC reflects feelings of confidence that stimuli in the (internal and external) environment are comprehensible, manageable and meaningful. Common resilience-related protective factors that are employed by this population include self-efficacy and adaptive coping [REF]. A recent study involved administering a 6-week programme that incorporated mindfulness and CBT techniques to build resilience in individuals living with chronic physical conditions including heart disease and diabetes [REF]. Findings emphasised positive experiences around well-being, condition management, and social engagement. In another study, a mind-body intervention involving dance and movement has also been shown to be effective in improving resilience in people suffering from chronic pain [REF].
INTEGRATE INTO THE ABOVE: Psychological flexibility (PF) is another area in which clinicians can work with to indirectly improve health and wellbeing through influencing one’s ability to respond flexibly to demands and alter mindsets and behaviours when necessary, subsequently impacting both physical and mental health. For example, research supports the use of Acceptance and Commitment Therapy (ACT) to target PF [REF], with PF mediating the extent to which ACT influences both mental and physical health outcomes, including anxiety, depression, pain and medical visits [REF].
Many interventions based on the principles of positive psychology have been applied to those living with chronic conditions and there are promising results. For example, mindfulness meditation has proven effective in reducing pain (Hilton et al., 2017; Veehof, Trompetter, Bohlmeijer & Schreurs, 2016; Zeidan & Vago, 2016) and optimism training can be effective among people with heart disease in increasing life satisfaction and hope, along with reducing anxiety (Mohammadi et al., 2018). Optimism has also been associated with higher quality of life among people with heart failure (Kraai et al., 2018).
Research has also focused on the relationship between health behaviours and mental health, with a systematic review of randomised controlled trials concluding that dietary changes have the potential to improve depression symptomology [REF]. For example, an RCT investigated the impact of the Mediterranean diet on adults with self-reported depression [REF]. Results highlighted a negative correlation between adherence to the Mediterranean diet and depression and quality of life scores at both the 3- and 6-month time points. Using exercise as a clinical target to improve mental health has also proven beneficial, with evidence to suggest exercise to be as effective as medication and psychotherapy in the treatment of mild to moderate depression [REF]. A meta-analysis on 25 RCTs found exercise to have a significant effect on reducing depression, even among those major depressive disorders [REF], with another review finding exercise to be beneficial in the treatment of mood disorders more generally [REF]. Given that depression is associated with a high incidence of cardiovascular diseases, diabetes and metabolic syndrome, using exercise as a treatment will be beneficial for the symptoms of both depression and the chronic illness [REF]. In a Brazil survey, almost half of those living with a mood or anxiety disorder also suffered from comorbid chronic pain [REF], and data from 17 countries provides evidence of mental health disorders increasing the likelihood of developing a chronic physical condition [REF], further highlighting associations between chronic illness and mental health and the importance of understanding both the physical and mental benefits of modifying health behaviours.
In summary, there is tremendous opportunity for improving the health and wellbeing of people living with chronic conditions by focusing on the individual. Traditional routes for improving physical health, such as physical activity, diet and sleep may now be considered as opportunities to support mental wellbeing, when combined with strategies for behaviour change. Treatments that build strengths, resilience, optimism and positive psychological attributes will provide useful strategies to promote health and wellbeing, as has been discussed previously [REF].
 
INTEGRATE THE FOLLOWING FROM ABOVE: Targeting Resilience & Sense of Coherence