• Medications do not work in people who do not take them.
• Non-adherence is actually the norm, and across many chronic conditions around 50% of medications are not taken as prescribed.
• Non-adherence can be intentional or un-intentional and these need to be differentiated because they are driven by different factors.

• Psoriasis (PsO) is a complex systemic condition and is associated with high levels of psychological and social morbidity and impaired quality of life.
• Comorbidities are also common, including PsO arthritic disease and increased cardiac risk.
• When considering medication adherence, we need to consider it in the context of all these other challenges.

• Topical therapies can be time-consuming [1].
• Can stain clothing and bedding [1].
• Patients are often unsure how much topical therapy to use, when to use it, and how often they should be using it [1].
• Unpredictable flares can make patients uncertain whether topical therapies are managing symptoms [1].
• Reported lack of support from clinicians [1].
• Concerns about potential adverse effects [1].
  • Short-term effects (e.g. skin irritation) / Long-term effects (e.g. organ damage in biologics).
• High levels of uncertainty [1].
  • Will my treatments stop working? / What will happen if they stop working?
• Distress associated with therapy taking can influence adherence (33-78% of PsO patients do not use their therapy as prescribed) [2].
• Adherence to treatment is a complex behaviour, especially for PsO and many patients report making strategic judgements about how they use topical therapies, even though not discussed with their clinician (both over and under-use).
• Treatment overuse has important implications for drug side-effects.

• The iMAP study surveyed 811 with moderate to severe PsO patients treated across 35 dermatology centres around England [3].
• Non-adherence can occur with all drugs, and this study found rates of almost 30% for conventional systemic therapies and 16% for biologic therapies [3].
• People who reported the strongest concerns about their systemic therapy were more likely to be classified as non-adherent, than those who reported weaker concerns and medication beliefs were not associated with unintentional non-adherence (e.g. forgetting) [3].
• The most important, potentially modifiable, factors influencing adherence was found to be belief about PsO treatment and medicines in general and mood drive intentional non-adherence (see Figure 1).
• People who reported weaker medication-taking habits/routines for taking their systemic therapy were more likely to be classified as non-adherent, than those who reported stronger habits/routines.

Think-feel-do cycle – Identify patterns in thoughts, feelings and behavior

• This is the first step to understand and therefore change the ways in which we can help cope better with medications and adherence to a long-term therapy.
• The loop can become a vicious cycle, see example Figure 2.
• Physicians need to work with patients to identify unhelpful behaviour patterns that can occur in response to thoughts and feelings, it is an important step in supporting medication adherence.
• People are often unaware of these patterns BUT when they are able to identify them, they can often intervene early to stop them.
• Identifying these patterns can provide targets for behaviour change.

Maintaining new behaviour – Helping to develop good routines and habits.

• Action planning – contextual cues (‘when, what, how will I know’ framework to aid habit formation), for example “I will take my tablets before I brush my teeth”
• By tying the behaviour to a contextual cue, stress and demands of that behaviour are reduced and the behaviour becomes automatic and unconscious.