Kaleidoscope - Volume 218 , Issue 3

How has the covid-19 pandemic affected individuals with pre-existing mental illnesses? An estimated 200 000 scientific papers on covid-19 had been published by December 2020,Reference Else1 but some studies were clearly more important and better designed than others. Pan et alReference Pan, Kok, Eikelenboom, Horsfall, Jörg and Luteijn2 assayed the effects of the pandemic on three existing longitudinal case–control cohort studies of over 1000 individuals with pre-existing depressive, anxiety or obsessive–compulsive (OCD) disorders. This was helpful as, to date, among the 200 000 papers, the significant number looking at mental health have often been based on convenience samples and self-selecting survey participants without pre-pandemic comparator data. Such studies have typically reported alarming rises in psychological distress, but their methodological limitations compromise the validity of the findings. Here, online questionnaires asked about perceived effect on mental health, fear of the virus and coping; and, crucially, repeated previously collected scales assessing various symptom domains including worry and loneliness. Fascinatingly, the control group without any pre-existing problems showed a greater increase in symptoms during the pandemic than those who already had such difficulties. Those with depression, anxiety and OCD remained unwell, with considerable illness burden – and they had considerable concerns about the virus and its potential effects – but overall this did not increase. Indeed, those who had the greatest prior illness burden actually showed a modest symptom decrease. There is no clear explanation for this latter finding, although the authors suggest that societal lockdowns might make the wider world more ‘in sync’ with those who have mental illnesses, staying at home might help some with structure and daily routine, and there might be some regression to the mean in this most unwell group