The day-to-day concurrence of bodily complaints and affect in patients with severe somatoform disorder.

Based on the concept of somatization, psychological distress can be experienced as symptoms of physical illness. This suggests a close-fitting intra-individual association between bodily complaints and mood in patients with somatoform disorder (SFD). The contemporaneous day-to-day complaints-mood association was investigated in patients with severe chronic SFD using an ecological momentary assessment (EMA) design. Eleven patients, who had recently received specialized tertiary care treatment for severe chronic SFD, kept an online electronic diary for four consecutive weeks. They were prompted at intervals throughout the day to complete questions on their momentary primary symptoms (pain and fatigue), and mood state (negative and positive). For each measure, day-mean aggregated values were computed and analyzed using linear multilevel (mixed model) regression analysis. Fixed factor results showed that symptoms were associated with both negative mood state (β = 0.47) and positive mood state (β = -0.59). Random results, however, indicated large inter-individual differences, with correlations varying between 0.17 and 0.99 for negative affect, and between -0.88 and 0.14 for positive affect. A substantial day-to-day contemporaneous association between symptoms and affect across subjects, as well as large inter-individual differences in this association, were demonstrated in patients with severe chronic SFD. EMA-data showing the relationship between both negative and (inverse) positive mood and complaints has potential clinical relevance: providing SFD patients with feedback consisting of their personal day-to-day concurrency graph may promote their understanding of their own complaints in a broader context than the somatic area.