Psychiatric comorbidities are common in multiple sclerosis (MS) and are associated with diminished quality of life and non-adherence to disease-modifying therapy (DMT). Depression is linked to immune activation in inflammatory disorders. We hypothesized that persons with self-reported MS not receiving DMT and those on lower efficacy DMT (low [LED] and moderate [MED]) had more symptoms of anxiety, depression, and fatigue, as compared to those on DMT and on high efficacy DMT (HED).
Our team sought to determine if symptoms of depression, anxiety, and fatigue in MS correlate with the use and efficacy of DMT.
We developed a web-based survey including the Patient Health Questionnaire-9 (PHQ-9), the Generalized Anxiety Disorder 7-item (GAD-7) scale, and the Modified Fatigue Impact Scale 5-item version (MFIS-5). Invitations to complete the survey were distributed electronically by MS organizations. DMTs were classified in LED (interferon beta-1a, interferon beta-1b, peginterferon beta-1a, glatiramer acetate), MED (teriflunomide, fingolimod, siponimod, dimethyl fumarate), and HED (alemtuzumab, ocrelizumab, rituximab, natalizumab, cladribine). Analyses were conducted using linear models adjusted for age, sex, ethnicity, disease duration, employment status, and whether the individual has an MS provider.
2121 persons completed the survey (age 51.1±12.4 years, 18% male, and 52% have had MS for >10 years). 1650 were on DMT (465 LED, 546 MED, 624 HED, 15 other). MFIS-5 and GAD-7 scores were lower for those on DMT as compared to those not on DMT (for MFIS-5: 0.79 points lower, 95% CI -1.37, -0.21; p=0.007; for GAD-7: 0.68 points lower; 95% CI -1.29, -0.07, p=0.03). Those on LED had -1.18 (95% CI -1.97, -0.38; p=0.004) lower PHQ-9 scores compared to those on no DMT. Among individuals on a DMT, those on HED had higher MFIS-5 and PHQ-9 scores relative to those on LED (for MFIS-5: 1.78 points higher, 95% CI 1.13, 2.24, p<0.001; for PHQ-9: 1.00 points higher; 95% CI 0.25, 1.74, p=0.009).
In this cross-sectional study, untreated patients had more fatigue and anxiety than those on DMT and greater depression than those on LED. LED-treated patients had lower fatigue and depression scores compared to those on HED. Indication biases may have influenced our results; longitudinal studies taking into account prior DMT history and indicators for specific DMTs should evaluate whether certain DMT classes affect future depression, anxiety, or fatigue levels.