Longitudinal changes in somatic symptoms and family disagreements among depression and community groups: a 23-year study

BACKGROUND: Few longitudinal studies describe the relationship between somatic symptoms and family disagreements. We examined changes over time in somatic symptoms, family disagreements, their interrelationships, and whether these patterns differed between individuals treated for depression (depression group) and individuals from the same community (community group). METHODS: We followed participants in the depression (N = 423) and community (N = 424) groups for 23 years (the community group was matched to the depression group on socioeconomic status, gender, and marital status). All participants were age 18+ and completed surveys at baseline, 1, 4, 10, and 23 year follow-ups. We assessed somatic symptoms and family disagreements at each time point and used latent growth curve modeling to examine change in these constructs over time. RESULTS: Somatic symptoms and family disagreements changed differently over time. Somatic symptoms decreased between baseline and the 10 year follow-up, but increased between the 10 and 23 year follow-ups, whereas family disagreements decreased linearly over time. Somatic symptoms and family disagreements were higher at baseline and declined at a faster rate in the depression compared to the community group. The relationship between changes in somatic symptoms and changes in family disagreements was also stronger in the depression group: a larger decrease in somatic symptoms was associated with a larger decrease in family disagreements. CONCLUSIONS: Longitudinal changes in somatic symptoms and family disagreements differ between depression and community groups. Individuals treated for depression had more somatic symptoms and family disagreements at baseline and improved at a faster rate compared to individuals in the community. Somatic symptoms and family disagreements may be important targets when treating depression, given the strong interrelationship among these factors in individuals with depression.