Mirtazapine Is Associated With Shorter Hospital Stay in Pediatric Avoidant Restrictive Food Intake...

Avoidant restrictive food intake disorder (ARFID) is a relatively new diagnostic entity, and no medication has been approved. Recent data suggest that mirtazapine, a tetracyclic antidepressant, could improve outcomes in ARFID. We conducted a retrospective chart review to examine the effects of mirtazapine on ARFID treatment in youth.

Hospital records from 87 children and adolescents with ARFID treated in an inpatient medical stabilization program were analyzed. Treatment outcome was tested for the effects of mirtazapine on weight gain, length of hospitalization, and duration of nasogastric feeding tube versus orally delivered nutrition. Other medications prescribed (selective serotonin reuptake inhibitors, dopamine D2 receptor partial agonist aripiprazole, and dopamine D2 receptor antagonists) and comorbid disorders (depression and anxiety) were included in the analysis.

Age was similar between individuals treated with or without mirtazapine (12.7 ± 1.0 years vs. 13.1 ± 1.0 years). Thirty-eight (44%) patients with ARFID were treated with mirtazapine. MANOVA indicated significant effects of mirtazapine (Wilks' λ = 0.741, F = 3.322, p = 0.007, partial η ² = 0.26, power = 0.908) and being associated with shorter hospital stays (F = 10.041, p = 0.002, partial η ² = 0.14) and a lower number of nasogastric feeding tube days (F = 6.202, p = 0.015, partial η ² = 0.09). Mirtazapine treatment was associated with a faster rate of weight gain (F = 4.121, p = 0.046, partial η ² = 0.05).

In our highly controlled environment, all patients reached a comparable target weight, but patients treated with mirtazapine did so faster. Further research should investigate the clinical effects and underlying mechanisms of mirtazapine in patients with ARFID.