Physical/psychological abuse and financial uncertainty and adversity

The largest predictor by far of both thinking about and engaging in self-harm was experiencing physical or psychological abuse, and this finding was consistent across all four age groups examined. Sensitivity analyses suggested that physical abuse is making larger contributions than psychological abuse to self-harm behaviours, whereas the sizes of the associations of both abuse types with self-harm thoughts were more similar. A range of literature outside of pandemic circumstances shows that different forms of abuse, including domestic violence, are predictors of self-harm behaviours and suicide.^{Reference Devries, Mak, Bacchus, Child, Falder and Petzold26,Reference Zatti, Rosa, Barros, Valdivia, Calegaro and Freitas27} That increases in domestic abuse would occur during stay-at-home orders was anticipated early in the pandemic,^{Reference Usher, Bhullar, Durkin, Gyamfi and Jackson28} and has been demonstrated in countries internationally. For example, the number of calls to emergency domestic abuse hotlines in the European Union had increased by 60% by the end of April 2020,^{Reference Mahase29} and intimate partner violence against women increased by 23% over the first 3 months of the first lockdown in Spain.^{Reference Arenas-Arroyo, Fernandez-Kranz and Nollenberger30}

Worsening economic circumstances have been identified as one of the causes of this increase in domestic abuse,^{Reference Arenas-Arroyo, Fernandez-Kranz and Nollenberger30} and financial stress was another predictor of self-harm thoughts and behaviours identified by our study and by other research conducted during the current pandemic.^{Reference Elbogen, Lanier, Blakey, Wagner and Tsai18} Notably, worrying about financial adversity such as losing one's job rather than actually experiencing such an adversity was more consistently associated with self-harm thoughts and behaviours across age groups. This suggests that, thus far, economic uncertainty rather than actual adversities is having a negative impact on people's mental health, and it is possible that these associations may change in magnitude as the economic consequences of the pandemic and recession unfold. Considerable evidence indicates that economic recessions are associated with increases in rates of self-harm and suicide, particularly in the working-age population.^{Reference Haw, Hawton, Gunnell and Platt8} Risk for both attempted suicide and suicide death is higher for those unemployed over the long term compared with those in shorter-term unemployment.^{Reference Mäki and Martikainen31,Reference Platt, Hawton, Hawton and van Heeringen32} However, an increase in self-harm and suicides during economic recessions is not inevitable.^{Reference Gunnell, Appleby, Arensman, Hawton, John and Kapur1}

Lessons learned from prior economic recessions suggest multiple opportunities for how governments can respond with policies to mitigate the mental health impact of the upcoming recession.^{Reference Wasserman, Iosue, Wuestefeld and Carli5} The increases in suicides that correspond to unemployment rates are not uniform across all countries but are instead modified by differential investment in social programmes to mitigate these effects.^{Reference Stuckler, Basu, Suhrcke, Coutts and McKee33} For example, following the 2008 financial crisis, an increase of 1% per capita in government spending designed to mitigate the effect of financial hardship was associated with a 0.2% decrease in suicide in Japan.^{Reference Matsubayashi, Sekijima and Ueda34} In the three decades leading up to the 2008 recession, every US$10 invested per person on programmes aimed to increase chances of gainful employment resulted in a 0.04% decrease in the effect of unemployment on suicides in EU countries.^{Reference Stuckler, Basu, Suhrcke, Coutts and McKee33} Thus, our findings highlight the potential danger of the economic impacts of COVID-19 on self-harm thoughts and behaviours and, as self-harm is an important risk factor for suicide, potentially for suicide too, and suggest the importance of addressing economic concerns among individuals urgently.

Age-related differences in associations

Although many of our findings were consistent across age groups, there were some discrepancies. For example, worrying about catching COVID-19 was associated with reduced likelihood of having self-harm thoughts and self-harm behaviours in adults aged 30–44, but this pattern was reversed in the oldest age group (aged 60+), among whom worries about falling ill were associated with increased likelihood of thoughts of harming themselves or that they would be better off dead (self-harm thoughts). This could have been influenced by public health messaging highlighting that older adults are at higher risk than younger adults for dying of the illness – a death that news coverage often portrayed as occurring alone and without the ability to say goodbye to loved ones. In contrast, having already had the illness was related to increased likelihood of both outcomes in the total sample, and this remained true in young (18–29) and middle-aged (45–59) adults for self-harm thoughts and for self-harm behaviours. It is therefore possible that the disease itself may play a role in increasing risk for self-harm thoughts and behaviours, whereas those who are particularly worried about falling ill with COVID-19 are more protective of their health and less likely to want to harm themselves. Evidence for the former, that COVID-19 illness leads to increased risk for mental health problems such as depression, self-harm thoughts and self-harm behaviours, has been documented across a range of studies.^{Reference Iob, Steptoe and Fancourt12,Reference Taquet, Geddes, Husain, Luciano and Harrison35}

Strengths and limitations

This study has a number of strengths, including the use of a large, well-stratified sample on sociodemographic groups that were weighted on the basis of population estimates of core demographics, and its longitudinal follow-up with repeated assessments of adversities, worries and self-harm thoughts and behaviours. We also used robust statistical methods to account for unobserved stable participant characteristics. However, sampling was not random and the data are therefore not representative of the general UK population. It is possible that individuals who were experiencing greater adversity and were more likely to have self-harm thoughts and behaviours were more likely to participate in the study. Nevertheless, this study did not aim to report prevalence of such experiences, but rather to identify the time-varying relationship between exposures and self-harm thoughts and behaviours. Crucially, the sample was heterogeneous and maintained its heterogeneity over time. There may have been other relevant forms of adversity and worry not captured in the current study, which may have resulted in an overestimation of the adversities and worries we did include. Finally, fixed-effects regression does not address direction of causality. Arellano–Bond models can be used to follow up fixed-effects models to account for this lack of directionality,^{Reference Arellano and Bond36} but because linear estimation is used, we could not utilise this approach as our outcomes were binary. However, although the relationship between worries and self-harm thoughts and behaviours may have involved some bidirectionality, there is little evidence to suggest that self-harm thoughts or behaviours increase the likelihood of individuals experiencing adversities.

Implications

Across the COVID-19 pandemic, there are concerns about potential future increases in suicide levels. Self-harm thoughts and behaviours are important and strong predictors of future suicide risk, so identifying modifiable risk factors for self-harm that can be addressed through public health interventions during the pandemic and beyond is vital.^{Reference Gunnell, Appleby, Arensman, Hawton, John and Kapur1,Reference Wasserman, Iosue, Wuestefeld and Carli5} Our findings suggest that increases in self-harm thoughts and behaviours across the first 59 weeks of the pandemic were related to financial uncertainty, physical or psychological abuse, concern for others, not being able to access essential items and worries about one's personal safety. Suggestions have already been made for how to adapt evidence-based suicide prevention strategies to current the pandemic.^{Reference Moutier37} For example, it has been recommended that universal interventions to mitigate the impact of poverty and unemployment on suicide risk should be implemented.^{Reference Wasserman, Iosue, Wuestefeld and Carli5} Our data suggest the importance of following such strategies to try to reduce self-harm thoughts and behaviours that have the potential to drive rising suicide rates over the coming months. The findings here also suggest the need for ongoing surveillance of how these well-established risk factors for suicide and self-harm may be exacerbated by the upcoming recession and as public health measures such as social distancing continue.