Predictors of nonadherence to antidepressants in depressed patients


Why is maintenance antidepressant therapy important?

  • Of patients with a depressive disorder 50% will have further episodes
  • The recurrence rate of depression is 80 to 90% after 3 episodes
  • Poor adherence to treatment of chronic conditions such as depressive disorder is a large problem
  • Nonadherence rates in recurrent depressed patients range from 39.7% to 52.7% with a mean of 46,5% over 2 years
  • Suboptimal dosing and duration of antidepressants increases the risk of relapse and recurrence.
  • Clinicians are only 50% accurate in their identification of potentially nonadherent patients.
  • Patch Testing
    Patch Test Services is соmmоnlу uѕеd to іdеntіfу саuѕеѕ of аllеrgіс contact dermatitis. Whеn performed рrореrlу, it саn bе interpreted аѕ ѕсіеntіfіс рrооf оf allergic соntасt dеrmаtіtіѕ. Thе раtсh test dоеѕ nоt nесеѕѕаrіlу duplicate сlіnісаl exposure іn whісh ѕwеаtіng, mасеrаtіоn, multiple applications оf a рrоduсt mау рlау rоlеѕ іn producing a ѕkіn reaction іn rеаl lіfе еxроѕurе of thе ѕkіn to a соntасt аllеrgеn.. Patch tеѕtіng however іѕ a better mеthоd оf fіndіng оut a cause оf an оffеndіng аllеrgіс contactant, thеn dоіng clinical trіаl. If аn allergen can bе соrrеlаtеd wіth a known exposure, роѕіtіvе patch tеѕt оr іmрrоvеmеnt bу avoidance оf ѕubѕtаnсеѕ соntаіnіng the аllеrgіс contactant іndеntіfіеd bу patch tеѕtіng then thе роѕіtіvе раtсh tеѕt іѕ validated. Unfortunately, mаnу dеrmаtоlоgіѕtѕ аѕ wеll аѕ allergists dо nеglесt tо perform patch tеѕtѕ tо іdеntіfу the causes оf аllеrgіс соntасt dermatitis. At Thе Asthma Cеntеr, wе hаvе hаd decades оf еxреrіеnсе dоіng patch tеѕtѕ and іdеntіfуіng significant аllеrgіс соntасt rеасtіоnѕ.
  • When a super-sensitive person comes in contact with the substance that causes the allergy (called an allergen), the immune system overreacts and releases a large amount of a chemical called histamine. Large amounts of histamine cause tissue swelling (inflammation) and tightening (constriction) of muscles and other tissues, including those in the breathing passages. If you aren’t sure how to treat your allergies, then consider contacting this Board Certified Allergist for help.

What are the potential risk factors for nonadherence in patients with recurrent depressive disorder? This question was recently researched and published in the Journal of Clinical Psychiatry.

The researchers assessed nonadherence with the Medication Adherence Questionnaire. Nonadherence on this scale indicates that patients missed 20% or more of the doses of their antidepressant medication. They followed 91 patients with at least 2 major depressive episodes in the last 5 years and were in remission. Follow up duration was 2 years.

In a multivariate analysis with backward elimination they found a higher level of personality pathology and higher education at baseline predictive for for nonadherence during a follow up of 2 years. These two factors explained 15% of the variance in nonadherence. All other variables such as axis 1 comorbidity, number of previous episodes, severity of residual symptoms, severity and duration of last episode, and medication did not increase the risk of nonadherence. There was no independent variable predicting nonadherence.

Limitations of this study
Besides the small sample which could have limited the power of the study resulting in a lack of identifying possible factors influencing nonadherence this study did not include other confounding factors for adherence in the patient doctor relationship such as the therapeutic alliance, patients attitudes towards the illness and the medication.
Ten Doesschate MC, Bockting CL, Koeter MW, Schene AH (2009). Predictors of nonadherence to continuation and maintenance antidepressant medication in patients with remitted recurrent depression. Journal of Clinical Psychiatry DOI: 19192463