Quantifying the level of difficulty to treat major depressive disorder with antidepressants: Treatment Resistance to Antidepressants Evaluation Scale

Subgrouping time-dependent prescribing patterns of first-onset major depressive episodes by psychotropics dissection

BACKGROUND

Subgrouping patients with major depressive disorder is a promising solution for the issue of heterogeneity. However, the link between available subtypes and distinct pathological mechanisms is weak and yields disappointing results in clinical application.

AIM

To develop a novel approach for classification of patients with time-dependent prescription patterns at first onset in real-world settings.

METHODS

Drug-naive patients experiencing their first major depressive episode (n = 105) participated in this study. Psychotropic agents prescribed in the first 24 mo following disease onset were recorded monthly and categorized as antidepressants, augmentation agents, and hypnosedatives. Monthly cumulative doses of agents in each category were converted into relevant equivalents. Four parameters were used to summarize the time-dependent prescription patterns for each psychotropic load: Stability, amount, frequency, and the time trend of monthly prescriptions. A K-means cluster analysis was used to derive subgroups of participants based on these input parameters of psychotropic agents across 24 mo. Clinical validity of the resulting data-driven clusters was compared using relevant severity indicators.

RESULTS

Four distinct clusters were derived from K-means analysis, which matches experts’ consent: "Short-term antidepressants use", "long-term antidepressants use", "long-term antidepressants and sedatives use", and "long-term antidepressants, sedatives, and augmentation use". At the first 2 years of disease course, the four clusters differed on the number of antidepressants used at adequate dosage and duration, frequency of outpatient service use, and number of psychiatric admissions. After the first 2 years following disease onset, depression severity was differed in the four subgroups.

CONCLUSION

Our findings suggested a new approach to optimize the subgrouping of patients with major depressive disorder, which may assist future etiological and treatment response studies.

Visualizing Patterns of Medication Switching Among Major Depressive Patients with Various Stability and Difficulty to Treatments

INTRODUCTION

Efforts have been made in assessing efficacy and tolerability to various antidepressants, but understanding personalized chances of stability to medication switching sequence is still inconclusive. This study aimed to identify naturalistic switching patterns of medication in stratifying MDD patients.

METHODS

MDD patients were stratified based on treatment difficulty evaluated with the "Treatment Resistance to Antidepressants Evaluation Scale for Unipolar Depression" (TRADES). The duration of the time of diagnoses until the final switch to another class of antidepressants was used as prediction of unstable to drug therapy. ROC analysis was used to determine the cutoff values. A continuous temporal events function from the visual analytic tool was employed to perform patterns of switching between distinct pharmacological class such as selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs).

RESULTS

TRADES scores of 4.5 and not-switching times of 12.5 months were used as cutoff values to divide patients into four subgroups: stable/easy-to-treat (SE), unstable/easy-to-treat (UE), stable/difficult-to-treat (SD) and unstable/difficult-to-treat (UD). A total of 80% and 76.9% of patients initially treated with the SSRIs paroxetine or fluoxetine, respectively, were predicted to be stable to drug therapy. Approximately 70%, 44.8% and 41.4% of patients initially treated with the SNRIs fluvoxamine, sertraline and venlafaxine, respectively, were predicted to be UD, and 60% of patients using duloxetine were predicted to be stable to drug therapy. Analysis of the switching phenomenon showed that SSRIs were the first prescribed medications and mostly taken by the stable subgroups, and SNRIs were the preferentially chosen switching alternative. Medication switching patterns in unstable MDD patients are discussed.

CONCLUSION

Paroxetine, fluoxetine and duloxetine users were mostly stable among MDD patients in Taiwan with various stability and difficulty to treatments. Although responsiveness to specific medication sequence is likely required for clinical application, the results provide a baseline for such studies.