Chronic spinal pain and depressive disorders — particularly chronic depression — may each represent a risk factor for the other condition, according to a study published in the Journal of Pain.
In this study, researchers evaluated interview data from the National Comorbidity Survey (NCS), which used a modified version of a structured psychiatric diagnostic interview, the Composite International Diagnostic Interview (CIDI). Data were collected from a stratified participant sample between 1990 and 1992 (NCS-1; n=8098; ages, 15-54). The participants were tracked and interviewed 10 years later, between 2000 and 2001 (NCS-2; n=5001) using customized interview questions based on responses from the NCS-1. For NCS-2, 5463 of the NCS-1 respondents were traced, with 166 of those respondents reported as deceased.
Although participants were not asked about chronic back or neck pain during NCS-1, they were asked during NCS-2 whether they had experienced chronic back or neck problems since the NCS-1 interview period. Participants who responded positively for back or neck problems were asked about the age at which they first experienced problems.
NCS-2 respondents were also queried about their age at onset of lifetime major depressive disorder (MDD) or dysthymic disorder. MDD and DD diagnoses were based on CIDI response patterns during both NCS-1 and NCS-2 interviews. The number of years between NCS-1 and the development of incident MDD or dysthymic disorder was examined.
Cox regression analysis was used to evaluate the role of sociodemographic variables (ie, age, gender, race/ethnicity, and years of education) in time-to-incident chronic pain post-NCS-1 and, and, in participants without MDD or dysthymic disorder at NCS-1, time-to-incident MDD or dysthymic disorder after NCS-1.
The weighted descriptive features of the 5001 participants were the following: average age, 33.13 years; average number of years of formal education, 12.8; 75.5% white, 11.6% black, 9.4% Hispanic, and 3.5% other race/ethnicity; 50% women. At NCS-1, 13.4% of participants had chronic spinal pain and 15.0% and 3.0% had MDD and dysthymic disorder, respectively. At NCS-2, 12.0% of participants had developed incident chronic spinal pain and 10.2% and 2.6% had MDD and dysthymic disorder, respectively.
Participants with vs without chronic spinal pain at NCS-1 were found to be more likely to develop subsequent incident dysthymic disorder at NCS-2 (risk ratio [RR], 1.81, Z=2.82). The development of incident chronic spinal pain post-NCS-1 was associated with female gender and having <16 years of education (P <.01). The development of incident MDD post-NCS-1 was associated with female gender and younger age (P <.001). Chronic spinal pain at NCS-1 was associated with incident dysthymic disorder (P <.05).
Study limitations include the lack of assessment of pain duration or intensity at NCS-1.
“[O]verall, chronic depression is more strongly linked to chronic spinal pain than is major depressive disorder,” noted the study authors.
Schmaling KB, Nounou ZA. Incident chronic spinal pain and depressive disorders: data from the National Comorbidity Survey [published online November 21, 2018]. J Pain. doi:10.1016/j.jpain.2018.11.002