# Stress

Source: https://synapse-lifestyle.com/en/reference-guide/stress

## Stress level

Chronic stress goes together with heightened inflammatory processes, accelerated ageing and dysregulation of metabolism and the immune system, and is thus an important factor in the development of cardiometabolic and neurodegenerative disease[1, 2, 3, 4, 5, 6]. Synapse therefore uses a biopsychosocial model[7, 8], in which physiological stress responses, subjectively experienced wellbeing and social connectedness all count, spread across three items: stress level, loneliness and wellbeing.

Tackling stress demonstrably improves how someone feels and functions. Whether it also prevents heart attacks has not been demonstrated.

#### Guidelines

Measuring stress objectively is not straightforward. The short Perceived Stress Scale (PSS-4) is quick to administer[9, 10, 11], but psychometrically the weakest of the PSS variants[12]. For anxiety there is a clinically validated classification of the GAD-7[13]:

| GAD-7 (0-21) | Clinical classification |
| --- | --- |
| 0 to 4 | No or minimal anxiety |
| 5 to 9 | Mild anxiety |
| 10 to 14 | Moderate anxiety |
| ≥ 15 | Severe anxiety |

#### How Synapse assesses this

Synapse measures both anxiety (GAD-7) and perceived stress (PSS-4) and brings the two signals together in the stress score. The zones follow the clinical GAD-7 classification. The choice of the short PSS-4 alongside the GAD-7, rather than the longer PSS-10, is an internal trade-off between completeness and questionnaire burden. The full stress questions follow only after a positive short screening; with a negative screening the stress level counts as good.

| Item | Reference |
| --- | --- |
| Anxiety (GAD-7) | ≤ 4 |
| Stress (PSS-4) | ≤ 2 |

## Loneliness

Loneliness is a major health risk and is associated with reduced quality of life, higher mortality and a greater risk of cardiovascular, metabolic and neurological disease[14, 15]. Strengthening connectedness demonstrably improves how someone feels; whether it also prevents heart attacks has not been demonstrated.

#### Guidelines

There is no numerical guideline for loneliness. The De Jong Gierveld scale is an internationally validated instrument with an emotional and a social subscale[16].

#### How Synapse assesses this

Synapse uses the three social loneliness questions from the De Jong Gierveld scale: being able to fall back on people, trusting people and feeling connected[16]. That measures the social facet (the network), not emotional loneliness. The answers together form a score from 0 to 6: the higher, the lonelier. The zone classification on that score is Synapse's own. For the individual rows Synapse shows no reference value.

## Wellbeing

Physical health and subjective wellbeing influence each other: reduced wellbeing is associated with an increased risk of cardiometabolic, mental, immunological and neurodegenerative disease, while high wellbeing appears favourable for survival[17]. Working on wellbeing demonstrably improves how someone feels; whether it also prevents disease has not been demonstrated.

#### Guidelines

The WHO-5 is a short and accessible instrument well suited to general wellbeing screening, with little overlap with other instruments. A score of 50 or lower out of 100 indicates reduced wellbeing, 28 or lower a possible depression[18].

#### How Synapse assesses this

Synapse uses the WHO-5. Each of the three WHO-5 questions asked (cheerful, energetic, interested) and of the two anxiety screening questions (GAD-2) scores 0 to 5 points, more as the answer is less favourable. When together they reach 4 points or more (out of 25), the questionnaire asks the follow-up questions: the PHQ depression screening with a suicidality protocol, loneliness and a non-validated burnout signal. The GAD-7 follows once the two anxiety questions alone reach 4 points together. Follow-up questions count in the scores exactly when they were asked, and never otherwise. The subdomain score follows these zones:

| WHO-5 (0-100, higher is better) | Assessment |
| --- | --- |
| > 72 | Optimal |
| 50 to 72 | Acceptable |
| 30 to 50 | Watch |
| < 30 | Priority |

| Item | Reference |
| --- | --- |
| WHO-5 questionnaire | ≥ 50 / 100 |

Developed and reviewed with the Synapse [medical advisory board](https://synapse-lifestyle.com/en/advisory-board).

## References

1. Parker, H. W. et al. Allostatic load and mortality: a systematic review and meta-analysis. Am J Prev Med 63, 131–140 (2022). https://doi.org/10.1016/j.amepre.2022.02.003
2. Yegorov, Y. E. et al. The link between chronic stress and accelerated aging. Biomedicines 8, 198 (2020). https://doi.org/10.3390/biomedicines8070198
3. Kivimäki, M. et al. The multiple roles of life stress in metabolic disorders. Nat Rev Endocrinol 19, 10–27 (2023). https://doi.org/10.1038/s41574-022-00746-8
4. Alotiby, A. Immunology of stress: a review article. J Clin Med 13, 6394 (2024). https://doi.org/10.3390/jcm13216394
5. Vaccarino, V. et al. Stress and cardiovascular disease: an update. Nat Rev Cardiol 21, 603–616 (2024). https://doi.org/10.1038/s41569-024-01024-y
6. Knezevic, E. et al. The role of cortisol in chronic stress, neurodegenerative diseases, and psychological disorders. Cells 12, 2726 (2023). https://doi.org/10.3390/cells12232726
7. Engel, G. L. The need for a new medical model: a challenge for biomedicine. Science 196, 129–136 (1977). https://doi.org/10.1126/science.847460
8. Rith-Najarian, L. R. et al. The biopsychosocial model of stress in adolescence: self-awareness of performance versus stress reactivity. Stress 17, 193–203 (2014). https://doi.org/10.3109/10253890.2014.891102
9. Vallejo, M. A. et al. Determining factors for stress perception assessed with the Perceived Stress Scale (PSS-4) in Spanish and other European samples. Front Psychol 9, 37 (2018). https://doi.org/10.3389/fpsyg.2018.00037
10. Cook, R. M. et al. A longitudinal examination of the psychometric properties of the English Perceived Stress Scale-4 in mental health counsellors using item response theory. Stress Health 40, e3468 (2024). https://doi.org/10.1002/smi.3468
11. Cohen, S. et al. A global measure of perceived stress. J Health Soc Behav 24, 385–396 (1983). https://doi.org/10.2307/2136404
12. Lee, E. H. Review of the psychometric evidence of the Perceived Stress Scale. Asian Nurs Res (Korean Soc Nurs Sci) 6, 121–127 (2012). https://doi.org/10.1016/j.anr.2012.08.004
13. Plummer, F. et al. Screening for anxiety disorders with the GAD-7 and GAD-2: a systematic review and diagnostic metaanalysis. Gen Hosp Psychiatry 39, 24–31 (2016). https://doi.org/10.1016/j.genhosppsych.2015.11.005
14. Holt-Lunstad, J. et al. Loneliness and social isolation as risk factors for mortality: a meta-analytic review. Perspect Psychol Sci 10, 227–237 (2015). https://doi.org/10.1177/1745691614568352
15. Hawkley, L. C. Loneliness and health. Nat Rev Dis Primers 8, 22 (2022). https://doi.org/10.1038/s41572-022-00355-9
16. De Jong Gierveld, J. et al. The De Jong Gierveld short scales for emotional and social loneliness: tested on data from 7 countries in the UN generations and gender surveys. Eur J Ageing 7, 121–130 (2010). https://doi.org/10.1007/s10433-010-0144-6
17. Steptoe, A. et al. Subjective wellbeing, health, and ageing. Lancet 385, 640–648 (2015). https://doi.org/10.1016/S0140-6736(13)61489-0
18. Topp, C. W. et al. The WHO-5 Well-Being Index: a systematic review of the literature. Psychother Psychosom 84, 167–176 (2015). https://doi.org/10.1159/000376585