The Effects of Lemon Essential Oil Inhalation on Attention in Children With Attention Deficit Hyperactivity Disorder (ADHD)
8 de mayo de 2026 actualizado 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.
Descripción general del estudio
Estado
Terminado
Condiciones
Intervención / Tratamiento
Descripción detallada
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 estudio
Intervencionista
Inscripción (Actual)
52
Fase
- No aplica
Contactos y Ubicaciones
Esta sección proporciona los datos de contacto de quienes realizan el estudio e información sobre dónde se lleva a cabo este estudio.
Ubicaciones de estudio
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Istanbul, Turquía (Türkiye)
- Basaksehir Çam Ve Sakura City Hospital
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Criterios de participación
Los investigadores buscan personas que se ajusten a una determinada descripción, denominada criterio de elegibilidad. Algunos ejemplos de estos criterios son el estado de salud general de una persona o tratamientos previos.
Criterio de elegibilidad
Edades elegibles para estudiar
- Niño
Acepta Voluntarios Saludables
Sí
Descripción
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
Plan de estudios
Esta sección proporciona detalles del plan de estudio, incluido cómo está diseñado el estudio y qué mide el estudio.
¿Cómo está diseñado el estudio?
Detalles de diseño
- Propósito principal: Cuidados de apoyo
- Asignación: Aleatorizado
- Modelo Intervencionista: Asignación paralela
- Enmascaramiento: Único
Armas e Intervenciones
Grupo de participantes/brazo |
Intervención / Tratamiento |
|---|---|
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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.
Otros nombres:
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Comparador de placebos: 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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¿Qué mide el estudio?
Medidas de resultado primarias
Medida de resultado |
Medida Descripción |
Periodo de tiempo |
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Change in D2 Attention Test Total Performance Score (TN-E)
Periodo de tiempo: 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 resultado secundarias
Medida de resultado |
Medida Descripción |
Periodo de tiempo |
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Change in Benton Visual Retention Test (BVRT) Score
Periodo de tiempo: 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
Aquí es donde encontrará personas y organizaciones involucradas en este estudio.
Patrocinador
Fechas de registro del estudio
Estas fechas rastrean el progreso del registro del estudio y los envíos de resultados resumidos a ClinicalTrials.gov. Los registros del estudio y los resultados informados son revisados por la Biblioteca Nacional de Medicina (NLM) para asegurarse de que cumplan con los estándares de control de calidad específicos antes de publicarlos en el sitio web público.
Fechas importantes del estudio
Inicio del estudio (Actual)
15 de febrero de 2022
Finalización primaria (Actual)
30 de septiembre de 2023
Finalización del estudio (Actual)
30 de septiembre de 2023
Fechas de registro del estudio
Enviado por primera vez
24 de diciembre de 2025
Primero enviado que cumplió con los criterios de control de calidad
8 de mayo de 2026
Publicado por primera vez (Actual)
14 de mayo de 2026
Actualizaciones de registros de estudio
Última actualización publicada (Actual)
14 de mayo de 2026
Última actualización enviada que cumplió con los criterios de control de calidad
8 de mayo de 2026
Última verificación
1 de diciembre de 2025
Más información
Términos relacionados con este estudio
Palabras clave
Términos MeSH relevantes adicionales
Otros números de identificación del estudio
- 10.06.2021-21
Plan de datos de participantes individuales (IPD)
¿Planea compartir datos de participantes individuales (IPD)?
NO
Descripción del plan 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.
Información sobre medicamentos y dispositivos, documentos del estudio
Estudia un producto farmacéutico regulado por la FDA de EE. UU.
No
Estudia un producto de dispositivo regulado por la FDA de EE. UU.
No
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