Depression and anxiety impact bodily symptoms differently in patients with fibromyalgia, according to a study from the University of Iowa.

This may explain why multidisciplinary treatments that include psychological interventions for fibromyalgia are effective only for a subset of patients, researchers said, suggesting that treatment should be tailored to the individual symptoms a patient is experiencing. More research is then needed to assess if such a tailored approach is beneficial for fibromyalgia patients.

The study reporting the findings, “Somatic symptom presentations in women with fibromyalgia are differentially associated with elevated depression and anxiety,” was published in the Journal of Health Psychology.

Researchers recruited 191 women with a fibromyalgia diagnosis. The majority of the patients, 65 percent, had been ill for more than five years.

Half of the study participants reported they were affected by depression or anxiety. This subgroup was made up of 24 percent who had high levels of both depression and anxiety; 17 percent who reported high levels of anxiety without high levels of depression; and 9 percent who said they were depressed but did not experience anxiety.

In addition to examining the levels of depression and anxiety, the research team measured fatigue, the presence of sleep disturbance, pain catastrophizing (exaggeration), fear of movement, and pain severity using validated tools.

Data showed that pain catastrophizing, fear of pain, and pain severity were linked with both anxiety and depression, and that both independently impacted pain and pain-related symptoms. The effect was, however, not additive.

This was a surprise to the team members, who thought that anxiety and depression — when present together — would have an amplifying effect to cause even more severe symptoms.

Fatigue and sleep problems, on the other hand, appeared to be impacted only by depression. Although some studies suggest that sleep problems may trigger depression in fibromyalgia patients, there may be other explanations for this association.

Researchers said that it also is possible that common mechanisms — such as central nervous system sensitization or inflammation — may give rise to both sleep problems and depression, in addition to fibromyalgia.

The observations made the team suggest that current multidisciplinary treatments with psychological interventions may be more effective for patients with low levels of anxiety and depression, and that more tailored approaches are needed for patients with higher levels of depression/anxiety.

“These results suggest the possible benefit of tailored targeted treatments for symptom management in persons with fibromyalgia. The differences identified in fatigue and sleep quality in relation to depression versus anxiety provide direction for such targeted clinical interventions,” the researchers wrote.

Future studies should now focus on evaluating if interventions, targeted for fibromyalgia patients with various levels of depression and anxiety, are more effective than current approaches.