The Effects of Lemon Essential Oil Inhalation on Attention in Children With Attention Deficit Hyperactivity Disorder (ADHD)
8 de maio de 2026 atualizado por: Başakşehir Çam & Sakura City Hospital
Lemon Essential Oil Inhalation Improves Sustained Attention in Children With Attention-Deficit/Hyperactivity Disorder: A Placebo-Controlled Trial
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.
Visão geral do estudo
Status
Concluído
Condições
Intervenção / Tratamento
Descrição detalhada
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.
Tipo de estudo
Intervencional
Inscrição (Real)
52
Estágio
- Não aplicável
Contactos e Locais
Esta seção fornece os detalhes de contato para aqueles que conduzem o estudo e informações sobre onde este estudo está sendo realizado.
Locais de estudo
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Istanbul, Turquia (Türkiye)
- Basaksehir Çam Ve Sakura City Hospital
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Critérios de participação
Os pesquisadores procuram pessoas que se encaixem em uma determinada descrição, chamada de critérios de elegibilidade. Alguns exemplos desses critérios são a condição geral de saúde de uma pessoa ou tratamentos anteriores.
Critérios de elegibilidade
Idades elegíveis para estudo
- Filho
Aceita Voluntários Saudáveis
Sim
Descrição
Inclusion Criteria:
- 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
Exclusion Criteria:
- 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
Plano de estudo
Esta seção fornece detalhes do plano de estudo, incluindo como o estudo é projetado e o que o estudo está medindo.
Como o estudo é projetado?
Detalhes do projeto
- Finalidade Principal: Cuidados de suporte
- Alocação: Randomizado
- Modelo Intervencional: Atribuição Paralela
- Mascaramento: Solteiro
Armas e Intervenções
Grupo de Participantes / Braço |
Intervenção / Tratamento |
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Experimental: 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.
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This intervention consists of a single-session, short-term olfactory exposure to 100% pure lemon essential oil (Citrus limon, ISO 9235 compliant, GC-MS confirmed composition: limonene 67.2%, β-pinene 12.3%, γ-terpinene 9.8%).
Five drops were applied to a sterile cotton pad and held approximately 5 cm from the participant's nose.
Participants inhaled the aroma for 5 minutes under direct supervision in a quiet, odor-free clinical setting.
This intervention was administered immediately prior to standardized neuropsychological assessments measuring attention and visual memory.
No ingestion or topical application occurred.
Outros nomes:
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Comparador de Placebo: 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.
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The placebo condition involved the same protocol as the intervention group, using five drops of distilled water applied to a sterile cotton pad.
The pad was held approximately 5 cm from the participant's nose, and inhalation lasted for 5 minutes.
The procedure was designed to mimic the intervention without olfactory stimulation, ensuring consistency in timing, setting, and administration method.
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O que o estudo está medindo?
Medidas de resultados primários
Medida de resultado |
Descrição da medida |
Prazo |
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Change in D2 Attention Test Total Performance Score (TN-E)
Prazo: Baseline and Day 30 (after intervention)
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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.
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Baseline and Day 30 (after intervention)
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Medidas de resultados secundários
Medida de resultado |
Descrição da medida |
Prazo |
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Change in Benton Visual Retention Test (BVRT) Score
Prazo: Baseline and Day 30 (after intervention)
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The Benton Visual Retention Test assesses visual memory and visuospatial construction skills.
Scores range based on correct reproductions of geometric figures.
The change in BVRT scores from baseline to Day 30 will be analyzed to assess the impact of lemon essential oil inhalation versus placebo.
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Baseline and Day 30 (after intervention)
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Colaboradores e Investigadores
É aqui que você encontrará pessoas e organizações envolvidas com este estudo.
Patrocinador
Datas de registro do estudo
Essas datas acompanham o progresso do registro do estudo e os envios de resumo dos resultados para ClinicalTrials.gov. Os registros do estudo e os resultados relatados são revisados pela National Library of Medicine (NLM) para garantir que atendam aos padrões específicos de controle de qualidade antes de serem publicados no site público.
Datas Principais do Estudo
Início do estudo (Real)
15 de fevereiro de 2022
Conclusão Primária (Real)
30 de setembro de 2023
Conclusão do estudo (Real)
30 de setembro de 2023
Datas de inscrição no estudo
Enviado pela primeira vez
24 de dezembro de 2025
Enviado pela primeira vez que atendeu aos critérios de CQ
8 de maio de 2026
Primeira postagem (Real)
14 de maio de 2026
Atualizações de registro de estudo
Última Atualização Postada (Real)
14 de maio de 2026
Última atualização enviada que atendeu aos critérios de controle de qualidade
8 de maio de 2026
Última verificação
1 de dezembro de 2025
Mais Informações
Termos relacionados a este estudo
Palavras-chave
Termos MeSH relevantes adicionais
Outros números de identificação do estudo
- 10.06.2021-21
Plano para dados de participantes individuais (IPD)
Planeja compartilhar dados de participantes individuais (IPD)?
NÃO
Descrição do plano IPD
Individual participant data (IPD) will not be shared for this study due to ethical considerations, privacy protection regulations involving minors, and the absence of prior consent for data sharing beyond the scope of this trial.
Additionally, the study was conducted with a small sample size from a single center, limiting the generalizability and reuse of anonymized data for broader analysis.
Informações sobre medicamentos e dispositivos, documentos de estudo
Estuda um medicamento regulamentado pela FDA dos EUA
Não
Estuda um produto de dispositivo regulamentado pela FDA dos EUA
Não
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