The burden of headache is associated to pain interference, depression and headache duration in chronic tension type headache: a 1-year longitudinal study

BACKGROUND: To investigate variables associated at one year (longitudinal design) with the physical or emotional component of burden in chronic tension type headache (CTTH). METHODS: One hundred and thirty (n = 130) individuals with CTTH participated in this longitudinal study. Clinical features were collected with a 4-weeks headache diary at baseline and 1-year follow-up. The burden of headache was assessed at baseline and one -year follow-up with the Headache Disability Inventory (HDI), physical (HDI-P) or emotional (HDI-E) component. Sleep quality (Pittsburgh Sleep Quality Index), anxiety and depression (Hospital Anxiety and Depression Scale-HADS), and quality of life (SF-36) were also assessed at baseline. Hierarchical regression analyses were conducted to determine the associations between the baseline variables and the headache burden at 1-year. Simple mediation models were also applied to determine the potential mediation effect of any intermediary variable. RESULTS: Regression analyses revealed that baseline pain interference and depression explained 32% of the variance in the emotional burden of headache, whereas baseline emotional burden of the headache, pain interference, and headache duration explained 51% of the variance in the physical burden of headache (P < .01) at 1-year. The mediation models observed that the effect of baseline pain interference on emotional burden of headache at 1-year was mediated through baseline depression, whereas the effect of baseline pain interference on the physical burden of headache at 1-year was mediated through baseline emotional burden of headache (both P < .05). CONCLUSIONS: The current study found a longitudinal interaction between pain interference and depression with the burden of headache in individuals with CTTH.