The Novelty of Bupropion As a Dopaminergic Antidepressant for the Treatment of Adult Attention Deficit Hyperactive Disorder

Diagnosis and Treatment of ADHD in the Pediatric Population

Attention-deficit/hyperactivity disorder (ADHD) is one of the most common neurodevelopmental disorders in childhood with approximately 6 million children (age 3 to 17 years) ever diagnosed based on data from 2016-2019. ADHD is characterized by a constant pattern of inattention and/or hyperactivity-impulsivity symptoms that interferes with development or functioning. Specific criteria from the Diagnostic and Statistical Manual of Mental Disorders, 5th edition Text Revision assist with the diagnosis with multiple guidelines available providing non-pharmacologic and pharmacologic recommendations for the treatment of ADHD in the pediatric population. While all guidelines similarly recommend behavioral and/or stimulant therapy as first-line therapy based on age, not all stimulant products are equal. Their differing pharmacokinetic profiles and formulations are essential to understand in order to optimize efficacy and safety for patients. Additionally, new stimulant products and non-stimulant medications continue to be approved for use of ADHD in the pediatric population and it is important to know their differences in formulation, efficacy, and safety to other products currently available. Lastly, due to drug shortages, it is important to understand product similarities and differences to select alternative therapy for patients.

Methylglyoxal-Mediated Dopamine Depletion, Working Memory Deficit, and Depression-Like Behavior Are Prevented by a Dopamine/Noradrenaline Reuptake Inhibitor

Methylglyoxal (MGO) is an endogenous toxin, mainly produced as a by-product of glycolysis that has been associated to aging, Alzheimer's disease, and inflammation. Cell culture studies reported that MGO could impair the glyoxalase, thioredoxin, and glutathione systems. Thus, we investigated the effect of in vivo MGO administration on these systems, but no major changes were observed in the glyoxalase, thioredoxin, and glutathione systems, as evaluated in the prefrontal cortex and the hippocampus of mice. A previous study from our group indicated that MGO administration produced learning/memory deficits and depression-like behavior. Confirming these findings, the tail suspension test indicated that MGO treatment for 7 days leads to depression-like behavior in three different mice strains. MGO treatment for 12 days induced working memory impairment, as evaluated in the Y maze spontaneous alternation test, which was paralleled by low dopamine and serotonin levels in the cerebral cortex. Increased DARPP32 Thr75/Thr34 phosphorylation ratio was observed, suggesting a suppression of phosphatase 1 inhibition, which may be involved in behavioral responses to MGO. Co-treatment with a dopamine/noradrenaline reuptake inhibitor (bupropion, 10 mg/kg, p.o.) reversed the depression-like behavior and working memory impairment and restored the serotonin and dopamine levels in the cerebral cortex. Overall, the cerebral cortex monoaminergic system appears to be a preferential target of MGO toxicity, a new potential therapeutic target that remains to be addressed.

Vortioxetine for attention deficit hyperactivity disorder in adults: A randomized, double-blind, placebo-controlled, proof-of-concept study

BACKGROUND

Stimulants remain the mainstay of treatment for attention-deficit hyperactivity disorder (ADHD) but are often associated with insufficient response or poor tolerability, leading to many patients not wishing to be treated with controlled substances.

AIMS

This randomized, placebo-controlled, proof-of-concept study (NCT02327013) evaluated the efficacy of a multimodal antidepressant, vortioxetine, in the treatment of ADHD, using a two-stage sequential parallel comparison design.

METHODS

Patients aged 18-55 years with a diagnosis of ADHD (DSM-5) and a total score ⩾24 on the Adult ADHD Investigator Symptom Rating Scale (AISRS) were randomized in study stage I with a 1:1:3 ratio to six weeks of treatment with vortioxetine 10 or 20 mg/day, or placebo ( n = 227). In study stage II, placebo non-responders (AISRS total score reduction <30% from stage I baseline) were re-randomized with a 1:1:1 ratio to six weeks of vortioxetine 10 or 20 mg/day, or placebo ( n = 59).

RESULTS

Across the two study stages combined, ADHD symptoms improved by approximately eight AISRS points in all treatment groups, showing no difference from placebo for either dose of vortioxetine, the study thus failing to meet its primary endpoint. However, both doses of vortioxetine separated from placebo in improving overall patient functioning, as measured by the Sheehan Disability Scale.

CONCLUSION

Studies are warranted to further investigate this suggested benefit of a multimodal antidepressant for patient functioning in ADHD while addressing issues of non-adherence and placebo response. The study confirmed vortioxetine 10 mg and 20 mg as generally well-tolerated.