Depression and anxiety in patients with fibromyalgia are associated with poor illness perception rather than pain severity, a study has found.

Fibromyalgia syndrome (FMS) is associated with depression and anxiety with prevalence reaching 60 percent and 70 percent, respectively. Although previous studies have shown an association between pain, coping and illness perception with depression and anxiety in chronic pain patients, no such associations have been investigated in FMS.

This was therefore the main focus of the study “Poor Illness Perceptions Are a Risk Factor for Depressive and Anxious Symptomatology in Fibromyalgia Syndrome: A Longitudinal Cohort Study,” published in the journal Frontiers in Psychiatry.

The study involved 280 patients diagnosed with FMS by a certified rheumatologist in The Netherlands. The patients completed a baseline questionnaire at the beginning of the study and a follow-up questionnaire after 18 months.

In the questionnaires, anxiety, depression, pain severity, coping style and illness perceptions all were assessed using standard scales.

Mean age of the participants was 42.6 years and 95.4 percent of them were female.

At the 18-month interval, 68 patients had signs of depression and 80 of anxiety.

Overall, the results showed that patients who believed their illness impacted their mental status and who had high levels of depression were more likely to suffer from depression in the future. Patients who suffer from anxiety and think that the treatment will not be effective also are more likely to suffer from more anxiety in the future.

Although the team expected pain to be among the risk factors associated with depression and anxiety in FMS patients, the association found in this patient group was not significant.

The findings are consistent with some previous studies showing that patients with chronic widespread pain who believe their illness affects their mental status are more likely to suffer from depression and anxiety.

However, the findings are not consistent with a previous study that found a link between coping and the risk of depressive and anxiety symptoms in FMS patients, possibly due to the fact that a different assessment method was used in the current study.

“Our data suggest that not pain severity or maladaptive coping, but poor illness perceptions are important in elevated depressive and anxious symptomatology. Patients with fibromyalgia who think their illness negatively affects their mental well-being are at increased risk for more depressive symptoms, and those who think treatment of their illness will not be effective are at increased risk for more anxiety symptoms” the researchers wrote.

The identification of risk factors that can affect depression and anxiety in FMS patients is important, because it can offer the opportunity to tackle the risk factors before they impact the mental well-being of patients.

“Strengthening illness beliefs and reducing catastrophic thinking seem to be important factors in the treatment of patients with FMS, allowing them to improve their health. Future research should further explore the effects of such interventions” the team concluded.