Should we increase the focus on diet when considering associations between lifestyle habits and deliberate self-harm?

Despite increasing awareness of high rates of physical illness and poor lifestyle behaviours among patients with a history of repeated deliberate self-harm (DSH), there is little research on specific lifestyle factors that are potentially problematic for this group. This paper aims to explore the relationship between lifetime repeated DSH and certain lifestyle factors, including balanced meals, eating breakfast, consumption of 'junk' food, weight, exercise, substance/alcohol use, smoking and social support, in a cohort of patients who presented to the Emergency Department (ED) with suicidal ideation or DSH.

From 2007 to 2016, data from lifestyle and mental health measures were collected from 448 attenders at an outpatient clinic for DSH or suicidal ideation following ED presentation. Lifestyle behaviours (Fantastic Lifestyle Checklist) and mental health (Depression and Anxiety Stress Scale), clinical diagnosis and number of previous DSH episodes were measured on arrival. The associations between lifestyle variables and the number of lifetime DSH episodes were examined.

Sex, age, depression symptoms, poor diet, and smoking were all associated with a higher average number of deliberate self-harm episodes across the lifespan. There were non-significant positive trends for the other poor lifestyle behaviours. There was no association between DSH episodes and diagnosis of depression or anxiety disorder. In a multiple linear regression model, the only factors that remained significant were age, smoking and eating balanced meals, however, the relationship between smoking and lifetime DSH was moderated by more immediate DSH behaviours.

In this sample of patients referred to a service following presentation to the ED with acute mental health concerns, balanced meals and smoking were the lifestyle behaviours that were found to have the strongest independent association with repeated DSH across the lifespan.