Lemon Essential Oil Inhalation Improves Sustained Attention in Children With Attention-Deficit/Hyperactivity Disorder: A Placebo-Controlled Trial
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 发起方
- 入组人数
- 52
- 试验地点
- 1
- 主要终点
- Change in D2 Attention Test Total Performance Score (TN-E)
研究概览
简要总结
This randomized, placebo-controlled clinical trial aims to evaluate the acute effects of lemon essential oil inhalation on sustained attention and visual memory in children diagnosed with Attention-Deficit/Hyperactivity Disorder (ADHD). Fifty-two medication-naive children aged 9-16 were randomized to receive either lemon oil or placebo inhalation before cognitive assessments. Primary outcome was sustained attention performance. The study found significant improvements in attention scores in the lemon oil group.
详细描述
This randomized, placebo-controlled, single-blind clinical trial investigates the acute effects of lemon essential oil (LEO) inhalation on sustained attention and visual memory in children with attention-deficit/hyperactivity disorder (ADHD). Essential oils, particularly those rich in monoterpenes such as limonene, have demonstrated neuroactive properties through cholinergic modulation and limbic-prefrontal engagement via the olfactory pathway.
Fifty-two children aged 9-16 years, newly diagnosed with ADHD and not receiving any pharmacological treatment, were randomized to either the LEO group or the placebo group. Participants in the LEO group inhaled 5 drops of 100% pure Citrus limon essential oil via a cotton pad for five minutes prior to cognitive testing. The placebo group received an identical application with odorless distilled water.
Cognitive performance was assessed at baseline and 30 days later using the D2 Attention Test (primary outcome) and the Benton Visual Memory Test (secondary outcome). The entire intervention was conducted under standardized conditions, with blinded outcome assessment and strict adherence to procedural fidelity.
This study is the first to evaluate the short-term cognitive effects of lemon essential oil inhalation in children with clinical ADHD and aims to provide evidence for potential non-pharmacological support strategies.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Supportive Care
- 盲法
- Single (Participant)
入排标准
- 年龄范围
- 9 Years 至 16 Years（Child）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Children aged 9 to 16 years
- •Diagnosis of Attention Deficit Hyperactivity Disorder (ADHD) based on DSM-5 criteria
- •Medication-naive (not currently using or previously treated with pharmacological agents for ADHD)
- •No chronic medical or psychiatric comorbidities
- •Capable of completing standardized cognitive assessments (e.g., D2 Attention Test, Benton Visual Memory Test)
- •Written informed consent obtained from a parent or legal guardian
- •Written assent obtained from the child
排除标准
- •Lack of written parental consent or child assent
- •Inability to comply with the study protocol (e.g., refusal to complete cognitive testing or intervention procedure)
- •Current or prior use of ADHD medication
- •Presence of moderate-to-severe ADHD symptoms requiring immediate pharmacological treatment (based on AACAP 2020 and NICE 2019 guidelines)
- •Presence of any chronic medical or psychiatric comorbid condition
- •Diagnosis not confirmed by a board-certified child and adolescent psychiatrist
研究组 & 干预措施
Lemon Essential Oil Inhalation (LEO)
Participants in this arm received a single-session inhalation of 100% pure lemon essential oil (Citrus limon) via a sterile cotton pad. Five drops of essential oil were applied to the pad, which was held approximately 5 cm from the participant's nose. The child inhaled the scent for 5 minutes under supervision in a clinical setting. Neuropsychological testing (D2 Attention Test and Benton Visual Memory Test) followed immediately after inhalation.
干预措施: Lemon Essential Oil Inhalation (Other)
Placebo Inhalation (Distilled Water)
Participants in this arm received a single-session inhalation of distilled water as placebo. Five drops of distilled water were applied to a sterile cotton pad, which was held approximately 5 cm from the participant's nose. The child inhaled the scentless solution for 5 minutes under supervision. Neuropsychological testing (D2 Attention Test and Benton Visual Memory Test) followed immediately after inhalation.
干预措施: placebo inhalation (Other)
结局指标
主要结局
Change in D2 Attention Test Total Performance Score (TN-E)
时间窗: Baseline and Day 30 (after intervention)
The D2 Attention Test evaluates sustained attention and concentration performance. The TN-E (Total Number of Correct Items minus Errors) score reflects attentional capacity. A higher post-intervention TN-E score indicates improved attention. The difference between baseline and Day 30 scores will be compared between the lemon essential oil group and placebo group.
次要结局
- Change in Benton Visual Retention Test (BVRT) Score(Baseline and Day 30 (after intervention))