Objective

Multiple sclerosis (MS) severely affect quality of life (QoL). Pharmacological treatments demonstrated benefits on clinical endpoints, however, without proving a significant effect on QoL, we test the effect of a cognitive behavioural therapy (CBT) on QoL and investigate the association between QoL and illness progression.

Materials/patients and methods

One-year multicenter controlled multivariate-matched study on relapsing remitting ms (RRMS) patient expended disability status scale (EDSS) < 4 ms duration < 2 years treated by interferon in 11 French centres. For each new patient in this centre, two best-matching patients on five-baseline severity variable (age, gender, EDSS, mood, illness and duration) were selected in the other centres. The self-filled two lives scale (TLS) QoL was used at m0-3-6-9-12-15, the post-baseline summary mean of QoL constituted the main endpoint intent to treat was considered. A mixed model assessed the combined effect of CBT + interferon compared to interferon alone. A univariate mediation model was assessed the mediating effect of the therapy on QoL. The effect of illness progression on QoL was assessed in modelling the effect of EDDSS for each visit on QoL at later visits, the opposite effect of QoL on illness progression assessed in modelling QoL at every visit on EDSS at time t + 1.

Results

19 patients were recruited in the tested centre and matched to 51 patients of the control centres. Improvements of 1.10 (95% cL [0.31-1.89], p = .009) and 1.43***[.72, 2.15] were observed in the CBT group compared with placebo on QoL and coping scale. The effect of CBT on QoL can be essentially explained by a mediating effect of coping of 81% [57,100]. Finally, QoL is negatively affected by illness progression measured on earlier visits (–0.95***[–1.21,0.63]), whereas EDDS is influenced by previous QoL values (–0.10***[0.14, –0.06]).

Discussion/conclusion

QoL remains the key objective in MS treatment. We provide evidence:

– of a clinically important beneficial sustained effect of a cognitive therapy on QoL;

– that the beneficial effect of CBT is essentially explained by increase of positive coping;

– while confirming an negative effect of progression illness on QoL on illness progression.

As a consequence, QoL is together the most important target for patients and a factor of slowing illness progression.