Safety and tolerance of combination of monoamine oxidase inhibitors and direct dopamine agonists in adults and older adults with highly resistant depression

INTRODUCTION

Dopamine (DA) is likely to be involved in some depressive dimensions, such as anhedonia and amotivation, which account for a part of treatment-resistant forms. Monoamine oxidase inhibitors (MAOI) and direct D2 and D3 receptors agonists (D2/3r-dAG) are known to help, but we lack safety data about their combined usage. We report on safety and tolerance of the MAOI+D2r-dAG combination in a clinical series.

METHOD

All patients referred to our recourse center for depression between 2013 and 2021 were screened to select those who did receive the combo. Data were extracted from clinical files.

RESULTS

Sixteen patients of 60±17 years of age (8 women, 7 with age>65years, all suffered from treatment resistant depression, 7 with bipolar disorder) received the combo. There were no life-threatening adverse effects (AE). However, AE were reported by 14 patients (88%) most of which were mild and consisted of insomnia, nausea, nervousness, confusion, impulse control disorder and/or "sleep attacks". One patient presented a serious AE requiring a short hospitalization for confusion. Intolerance led to failure to introduce treatment in two patients (13%). The retrospective non-interventional design, the variety of molecules, and the modest sample size limited the scope of these results.

CONCLUSION

There was no life-threatening safety issue in combining MAOI and D2/3r-dAG, especially regarding cardiovascular side effects. The systematic screening of AE might account for their frequency, but these precluded the treatment in only two patients. Comparative studies are needed to assess the efficacy of this new combination.

Potential efficacy of dopaminergic antidepressants in treatment resistant anergic-anhedonic depression results of the chronic anergic-anhedonic depression open trial - CADOT

Introduction

Among treatment-resistant depression (TRD), we identified anergic-anhedonic clinical presentations (TRAD) as putatively responsive to pro-dopaminergic strategies. Based on the literature, non-selective monoamine oxidase inhibitors (MAOI) and dopamine D2 receptor agonists (D2RAG) were sequentially introduced, frequently under the coverage of a mood stabilizer. This two-step therapeutic strategy will be referred to as the Dopaminergic Antidepressant Therapy Algorithm (DATA). We describe the short and long-term outcomes of TRAD managed according to DATA guidelines.

Method

Out of 52 outpatients with TRAD treated with DATA in a single expert center, 48 were included in the analysis [severity - QIDS (Quick Inventory of Depressive Symptomatology) = 16 ± 3; episode duration = 4.1 ± 2.7 years; Thase and Rush resistance stage = 2.9 ± 0.6; functioning - GAF (Global Assessment of Functioning) = 41 ± 8]. These were followed-up for a median (1st - 3rd quartile) of 4 (1-9) months before being prescribed the first dopaminergic treatment and remitters were followed up 21 (11-33) months after remission.

Results

At the end of DATA step 1, 25 patients were in remission (QIDS <6; 52% [38-66%]). After DATA step 2, 37 patients were in remission (77% [65-89%]) to whom 5 patients with a QIDS score = 6 could be added (88% [78-97%]). Many of these patients felt subjectively remitted (GAF = 74 ± 10). There was a significant benefit to combining MAOI with D2RAG which was maintained for at least 18 months in 30 patients (79% [62-95%]).

Conclusion

These results support TRAD sensitivity to pro-dopaminergic interventions. However, some clinical heterogeneities remain in our sample and suggest some improvement in the description of dopamine-sensitive form(s).