Barriers and strategies to medication adherence amongst people with multiple sclerosis and cognitive problems

•There are greater barriers to DMT adherence for people with cognitive problems.•Issues of attention and distraction influenced forgetting treatment.•Anticipatory anxiety and difficulties accepting diagnosis hinder use of reminders.•Intravenous treatment was a significant predictor of adherence.•Addressing cognition, mood, treatment burden, and adjustment, may improve adherence. Adherence to disease-modifying treatment (DMT) amongst people with multiple sclerosis (MS) varies greatly. Although research often identifies 'forgetting' as a reason for poor adherence, few studies have considered how cognitive problems impact adherence. To investigate prevalence of and barriers to adherence, including for people with MS-related cognitive problems, and to identify adherence-related strategies. Recruited via the UK MS Register and MS Society groups, participants completed a Medication Adherence Questionnaire and the Perceived Deficits Questionnaire. A subset were interviewed. : Of 257 participants, 94 % reported being adherent, although 59 % missed ≥1 dose, and 25 % reported cognitive problems. Adherence was lower amongst those with cognitive problems, who experienced more barriers: memory problems; negative feelings about taking medication; and not wanting medication to interfere with activities. Such barriers, along with mood, cognition, and method of DMT administration, explained 17 % of variance in adherence, with intravenous treatment a significant predictor. Cognitive problems explained a unique proportion of variance; however, was non-significant when anxiety was factored in. Interviews highlighted how anxiety about side-effects and injections, and difficulties accepting the diagnosis, hindered use of reminders. Interventions for cognition and mood problems, minimising treatment burden and supporting adjustment to diagnosis, may improve adherence.