Vortioxetine Add-On to Methylphenidate for the Treatment of Symptoms of Sickness Behavior in Attention-Deficit Hyperactivity Disorder: Report of Two Cases

Youth with Attention-Deficit Hyperactivity Disorder (ADHD) may suffer from comorbid difficulties, such as anxiety-depressive symptoms, social withdrawal, and somatic complaints. Although stimulants remain the ADHD cornerstone treatment, mental fatigue, school problems and low self-esteem may persist, often being the most unacceptable symptoms for these patients. We present two cases of adolescents (14 and 15 years old) with methylphenidate-treated ADHD, where cognitive fatigability, depressive thoughts, anxiety, irritability, and poor social relationships remained. Based on clinical observation and the completion of parent and child rating scales, the aforementioned manifestations appeared to progressively reduce by the time of the subsequent control visits planned 1, 3, and 5 months after, following the use of vortioxetine (up to 10 mg/day) as add-on therapy to methylphenidate. No significant side effects were reported in both cases in a follow-up period of 3 months, also supporting the stability of the observed clinical improvement. Vortioxetine monotherapy has already been tested for the treatment of anxiety-depressive symptoms in youth, as well as ADHD in adulthood. The cases presented here suggest that vortioxetine could also be an effective option for ADHD treatment in childhood and adolescence, warranting further investigation of its potential benefits as both a monotherapy and adjunctive therapy to stimulants.