O’Callaghan, P.  “Adherence to stimulants in adult ADHD.”  J Atten Def Hyp Disord. (2014) 6:111-120.

This study uses a mixed-method design to investigate the factors that influence stimulant medication adherence in adults with ADHD.  The author notes that adherence rates for pharmacotherapy in adults with ADHD is reported to be less than 12% which is a significant concern for clinicians treating this population.  Stimulants have been shown to be highly effective in adults with ADHD with more than 70% experiencing a positive response, and with effect sizes in the range of 0.8-0.9 (Faraone, et al, 2006).  Despite these impressive results, less than 50% of adult patients prescribed a stimulant medication are taking them after 3 months, and by 18 months, only 20% are still receiving treatment (Weisler, et al, 2006).  This study sought to examine the reasons for low adherence using a combination of quantitative and qualitative methods in a sample of 67 adults (67% women) between the age of 19 and 64 years who were recruited from the community.   Subjects were given the Adult ADHD Quality of Life Scale (AAQoL) (Brod et al 2005) and were asked if they were taking stimulant medications daily, as needed or not at all.  Analysis of the total AAQoL and subscale scores showed no significant differences among the three adherence categories, indicating that adherence to medications was NOT correlated with reported quality of life.  

The qualitative phase of the study involved a telephone interview of a subset of 18 adults (61% women) who were queried about their experiences with stimulant medications and about their perceptions of the benefits and adverse effects of taking them.  They were also asked to explain how they made the decision to use or not use stimulants.  The responses were examined using a thematic analysis program that classified the subjects’ answers into five categories of the Health Belief Model (Munro et al 2007): severity of ADHD symptoms, barriers of stimulants, benefits of stimulants, “cues to action” (that is, factors that activate the patient’s readiness to change), and self-efficacy (or confidence in one’s ability to take action).   

The study found that all participants encountered barriers in their experience of taking stimulant medication.  Physical side effects were highly reported by patients with a high AAQoL whereas psychological side effects were reported only by patients with low AAQoL scores.  The positive benefits of stimulants were seen more often in patients with high quality of life yet, severity of ADHD symptoms was not associated with medication adherence.  The most salient “cue to action” found in the study pertained to the quality of the clinician-patient relationship.  The majority of patients with high quality of life had positive experiences with their health providers, whereas those with low quality of life reported frustration and dissatisfaction with their clinicians.  This proved to be the most influential factor in reported ADHD quality of life.  As it turns out, self-efficacy was not a significant theme reported by study participants.  

This article provides insights into the reasons for stimulant medication adherence or non-adherence in adult patients with ADHD.  It finds that the clinician-patient relationship is a strong predictor of ADHD quality of life but NOT of treatment adherence, and that perception of barriers to stimulant treatment is linked to the individual’s quality of life.  Despite the limitations of the study (small sample size, predominance of females in the sample, lack of clear generalizability), it offers a glimpse into the contextual factors that influence treatment adherence and it underscores the critical importance of good communication between clinician and patient so as to promote the best possible outcomes.

  

References

Brod M, Perwien A, Adler L, et al (2005).  Conceptualization and assessment of quality of life for adults with attention-deficit/hyperactivity disorder.  Prim Psychiatry 12:58-64.

Faraone S, Biederman J, Mick E (2006).  The age-dependent decline of attention deficit hyperactivity disorder: a meta-analysis of follow-up studies.  Psychol Med 36:159-165.

Munro S, Lewin S, Swart T, Volmink J (2007).  A review of health behavior theories: how useful are these for developing interventions to promote long-term medication adherence for TB and HIV/AIDS?  BMC Pub Health 7:1-6.

Weisler R, Biederman J, Spencer T, et al (2006). Mixed amphetamine salts extended-release in the treatment of adult ADHD: a randomized, controlled trial. CNS Spectr 11:625-639.