Health-promoting behaviours mediate association between symptom severity and QoL in mental illness

Health-promoting behaviours mediate the association between psychiatric symptoms and quality of life (QoL) in people with mental health illnesses (PMI), researchers from the Chinese University of Hong Kong (CUHK) have reported.

“Despite the well-known benefits of healthy lifestyle on health and QoL, research has shown that PMI have poorer lifestyle than the general population,” wrote the researchers. “We hypothesized that more severe symptoms [of mental illness] may be associated with a lower level of health-promoting behaviours, which in turn is associated with poorer QoL.”

In a local cross-sectional study, 591 Chinese PMI with DSM-IV-TR Axis I diagnosis (mean age, 46.0 years; female, 55.1 percent; mean duration of mental illness, 15.4 years) were recruited from the community. A majority of the participants were diagnosed with schizophrenia (70.3 percent), followed by major depression (13.5 percent) and bipolar disorders (7.1 percent). The participants were classified into low or high symptom severity groups, with no significant difference in baseline characteristics between groups. [Psychopathology 2022;doi:10.1159/000525495]

Results of the study showed that patients in the high symptom severity group engaged in significantly fewer health-promoting behaviours (Pillai’s Trace, 0.215; F=9.7266; p<0.001), including staying happy (p<0.0001), getting plenty of sleep (p<0.0001), eating plenty of fibre (p<0.001), controlling stress (p<0.001), participating in social activities (p<0.01), and exercising regularly (p<0.05) vs the low symptoms burden group.

The high symptom severity group also showed a significantly lower QoL (Pillai’s Trace, 0.271; F=26.70; p<0.001), including physical functioning, role limitation due to physical and emotional problems, bodily pain, general and mental health, vitality, and social functioning (all p<0.001), vs the low symptom burden group.

“It is likely that severe psychiatric symptoms, especially affective symptoms, as well as lack of energy and motivation, lead to withdrawal from health-promoting behaviours, thereby affecting patients’ QoL,” explained the researchers.

As demonstrated in a structural model, psychiatric symptoms were negatively related to health-promoting behaviours (-0.56; p<0.001), which in turn was positively related to QoL (0.16; p<0.01). Psychiatric symptoms were also negatively related to QoL (-0.73; p<0.001). “These findings highlight the importance of advocating health-promoting behaviours to improve QoL among Chinese PMI,” the researchers noted.

Of note, gender difference was also observed in the study. The association between psychiatric symptoms and health-promoting behaviours was strong among female participants (-0.46 for men vs -0.60 for women), while the association between health-promoting behaviours and QoL was strong in male participants (0.21 for men vs 0.15 for women). “The findings support the fact that women are more susceptible to the influence of symptom severity, and men might [enjoy more] benefits from health-promoting behaviours than women,” the researchers suggested.

“There is an urgent need to advocate health-promoting behaviours to improve the QoL of PMI,” suggested the researchers. “To maximize the effect of such interventions, gender difference should also be taken into account. Healthcare providers should pay more attention to improving psychiatric symptoms among female PMI, while male patients should be given more resources and opportunities to engage in health-promoting behaviours such as exercise and smoking cessation.”