Factors associated with initial medication adherence with first-line therapy for depression.

Area of Science:

• Psychiatry
• Pharmacology
• Health Services Research

Background:

• Initial medication adherence (IMA) to antidepressants in Major Depressive Disorder (MDD) is crucial but understudied.
• Understanding factors influencing optimal IMA is vital for acute treatment phases.

Purpose of the Study:

• To investigate factors associated with optimal initial medication adherence (IMA) in Major Depressive Disorder (MDD) patients starting antidepressant therapy.
• To identify specific antidepressant medications and patient characteristics linked to better adherence.

Main Methods:

• Retrospective cohort study using Merative MarketScan Data (2017-2019).
• Included adults (≥18 years) with MDD initiating selective serotonin reuptake inhibitors or serotonin-norepinephrine reuptake inhibitors.
• Optimal IMA defined as proportion of days covered (PDC) ≥80% within the first three months; multivariable logistic regression used.

Main Results:

• 60.71% of 397,976 MDD patients achieved optimal IMA.
• Higher odds of optimal IMA were associated with escitalopram, fluoxetine, venlafaxine, and levomilnacipran.
• Lower odds were linked to paroxetine and desvenlafaxine; patient demographics and comorbidities also influenced adherence.

Conclusions:

• Approximately 61% of MDD patients achieved optimal initial antidepressant adherence.
• Significant variations in IMA exist across different antidepressant agents and patient profiles.
• Findings underscore the importance of IMA and the need for targeted interventions to enhance adherence in MDD treatment.