Adherence or compliance, which-ever term one prefers, presents medicine with a number of challenges, nicely detailed in Kane et al's review. Evident when reading between the lines, although not explicitly stated, is the fact that compliance behaviour is difficult to study. Apart from the prescription of depot antipsychotics, which is really the only way to monitor compliance reliably, there is still no foolproof way to measure adherence. This methodological shortcoming explains why not much progress has been made in the past decades in establishing the foundations of compliance behaviour and the determinants of impaired adherence and, based on the knowledge of both of these, in conducting clinical studies which can shed light on the usefulness of compliance enhancing interventions.
As most of the relevant evidence has been summarized by Kane et al, I am only left to add or underscore a few points. Firstly, with respect to factors jeopardizing compliance, a few thoughts on attitudes towards treatment warrant consideration. Obviously, patients' attitudes impinge significantly on adherence behaviour, but one must also consider the attitudes of the patients' social environment, including relatives, friends and other patients. The latter, for instance, will likely relate their personal experiences with treatment modalities to the patient in question and may thereby shape his/her attitudes and compliance behaviour. Concerned relatives, having studied Internet sources of often dubious reliability, are also likely to interact in this process. Importantly, and this is often overlooked, the involvement of multiprofessional treatment teams poses a specific challenge in the context of compliance behaviour, as team members, if they are not well aligned with regard to treatment means and goals, may undeliberately convey mixed messages to patients, which may contribute to patients' insecurities with regard to treatment priorities. Par example, a social worker will focus on a patient's ability to hold a job, while a psychotherapist will emphasize coping skills and a nurse will make sure that medications are taken regularly. Accordingly, a patient will be confronted with three different intervention priorities and may therefore give undue preference to one over the other. As much as this is depicted in black and white, clinical reality often comes close, and this must be accounted for in team-based approaches.
Patients' attitudes can be influenced by rational or seemingly irrational factors. On the rational side, they can be influenced by previous experience with an antipsychotic or by information acquired via various media. On the irrational side, attitudes can be even influenced, for instance, by the shape or colour of medications or by the assumption that antipsychotics given in doses of 5 or 10 mg/day are “less strong” or “less dangerous” than those prescribed in daily doses of 600 or 800 mg/day.
The conviction to have to take drugs regularly is also driven by the seriousness attributed to one's illness, and schizophrenia patients have been shown to take their illness less seriously than, for instance, people with diabetes or hypertension . Furthermore, all antipsychotics block reward dopamine systems, thereby inducing negative reinforcement.
Paradoxically, some side effects may have a compliance improving impact. For instance, the increased attention given to patients who report adverse events may lead to more and longer contact with the treating clinician, thereby exerting a positive impact on the doctor/patient relationship.
It is key to understand that compliance is a dynamic treatment variable. Adherence behaviour changes over time and is also dependent on treatment circumstances. Therefore, compliance monitoring must be an ongoing treatment measure. As patients quickly learn to give expected and accepted answers to questions like “Do you take your medications regularly?”, alternative approaches have been suggested. These include questions like “When you forget your medication, what do you do?” or “Do you think that taking medication over a prolonged period of time is potentially harmful?” .
All of the issues described above, together with those reviewed by Kane et al, underscore the key importance of two factors to ensure optimal compliance behaviour. Both are based on communications strategies, namely, a good clinician/patient relationship and the provision of sound information. Both need to be an integral and continuous component of the management of patients suffering from severe mental disorders.