{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,29]],"date-time":"2026-10-29T20:33:29Z","timestamp":1793306009526,"version":"4.5.0"},"reference-count":57,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2025,10,2]],"date-time":"2025-10-02T00:00:00Z","timestamp":1759363200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Psychiatry"],"abstract":"<jats:sec><jats:title>Introduction<\/jats:title><jats:p>Cannabis-based medicine (CBM) is recommended for the treatment of tics in otherwise treatment-resistant adult patients with Tourette syndrome (TS). However, evidence in children with TS is very limited. Long-term effects of CBM in this population are unknown.<\/jats:p><\/jats:sec><jats:sec><jats:title>Case presentations<\/jats:title><jats:p>We present two cases of long-term follow-up over six and five years, respectively, in male adolescents with TS who were administered CBM starting at the age of eight and 12 years, respectively. In one patient CBM treatment was initiated with pure tetrahydrocannabinol (THC) and was later changed to current treatment with an oral THC-dominant cannabis extract (THC:cannabidiol (CBD)=25:&amp;lt;0.5) with a daily dose of 0.5-0.6 mL (corresponding to 12.5\u201315 mg THC\/day). The other patient was from the beginning up to now medicated by his parents, who are physicians, with vaporized THC-dominant (24%) medicinal cannabis flowers with a dose of 0.2 g between once to thrice per day (corresponding to 48\u2013144 mg THC\/day). While in one patient, there was a moderate dose increase over the years, in the other patient dosages were adjusted individually depending on tic severity. In both patients, CBM treatment resulted in continued benefit with significant improvement of tics and psychiatric comorbidities without severe adverse effects. Academic performance of both adolescents was excellent. Neurocognitive assessments demonstrated average results in the domain of working memory and average to above average results in the domain of processing speed.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusions<\/jats:title><jats:p>We present two cases of minors with TS who started CBM treatment at the age of eight and 12 years, respectively, and continued treatment for five to six years resulting in clinically relevant symptom improvement without any severe adverse effects or negative impact on cognitive and academic performance.<\/jats:p><\/jats:sec>","DOI":"10.3389\/fpsyt.2025.1647969","type":"journal-article","created":{"date-parts":[[2025,10,2]],"date-time":"2025-10-02T08:23:36Z","timestamp":1759393416000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":5,"title":["Long-term use of cannabis-based medicines in two children with Tourette syndrome: a case report"],"prefix":"10.3389","volume":"16","author":[{"given":"Lara-Katharina","family":"Woerner","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Natalia","family":"Szejko","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Carolin","family":"Fremer","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Simon","family":"Schmitt","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kirsten R.","family":"M\u00fcller Vahl","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2025,10,2]]},"reference":[{"key":"B1","article-title":"DSM-5 diagnostic classification","volume-title":"Diagnostic and Statistical Manual of Mental Disorders","year":"2015"},{"key":"B2","doi-asserted-by":"publisher","DOI":"10.1093\/med\/9780199796267.003.0005","article-title":"Clinical course and adult outcome in tourette syndrome","author":"Bloch","year":"2013","journal-title":"Tourette Syndrome"},{"key":"B3","doi-asserted-by":"publisher","first-page":"497","DOI":"10.1016\/j.jpsychores.2009.09.002","article-title":"Clinical course of Tourette syndrome","volume":"67","author":"Bloch","year":"2009","journal-title":"J Psychosom Res"},{"key":"B4","doi-asserted-by":"publisher","DOI":"10.1212\/WNL.0000000000007466","article-title":"Practice guideline recommendations summary: Treatment of tics in people with Tourette syndrome and chronic tic disorders","volume":"92","author":"Pringsheim","year":"2019","journal-title":"Neurology"},{"key":"B5","doi-asserted-by":"publisher","DOI":"10.1007\/S00787-021-01832-4","article-title":"European clinical guidelines for Tourette syndrome and other tic disorders: summary statement","volume":"31","author":"M\u00fcller-Vahl","year":"2022","journal-title":"Eur Child Adolesc Psychiatry"},{"key":"B6","doi-asserted-by":"publisher","DOI":"10.1007\/S00228-024-03710-9","article-title":"Efficacy of cannabis-based medicine in the treatment of Tourette syndrome: a systematic review and meta-analysis","volume":"80","author":"Serag","year":"2024","journal-title":"Eur J Clin Pharmacol"},{"key":"B7","doi-asserted-by":"publisher","DOI":"10.5772\/intechopen.79895","article-title":"Possible role of the endocannabinoid system in tourette syndrome","author":"Szejko","year":"2019","journal-title":"Recent Adv Cannabinoid Res"},{"key":"B8","doi-asserted-by":"publisher","DOI":"10.1517\/14656566.4.10.1717","article-title":"Cannabinoids reduce symptoms of Tourette\u2019s syndrome","volume":"4","author":"M\u00fcller-Vahl","year":"2003","journal-title":"Expert Opin Pharmacother"},{"key":"B9","doi-asserted-by":"publisher","DOI":"10.1016\/BS.IRMVD.2022.04.002","article-title":"Cannabinoids: Possible role in the pathophysiology and therapy of Gilles de la Tourette syndrome","volume":"4","author":"Szejko","year":"2022"},{"key":"B10","doi-asserted-by":"publisher","DOI":"10.1089\/can.2018.0050","article-title":"Treatment of Gilles de la Tourette Syndrome with Cannabis-Based Medicine: Results from a Retrospective Analysis and Online Survey","volume":"4","author":"Milosev","year":"2019","journal-title":"Cannabis Cannabinoid Res"},{"key":"B11","doi-asserted-by":"publisher","DOI":"10.1002\/MDS.28681","article-title":"Monoacylglycerol lipase inhibition in tourette syndrome: A 12-week, randomized, controlled study","volume":"36","author":"M\u00fcller-Vahl","year":"2021","journal-title":"Mov Disord"},{"key":"B12","doi-asserted-by":"publisher","DOI":"10.1038\/sj.npp.1300047","article-title":"Treatment of tourette syndrome with delta-9-tetrahydrocannabinol (\u03949-THC): No influence on neuropsychological performance","volume":"28","author":"M\u00fcller-Vahl","year":"2003","journal-title":"Neuropsychopharmacology"},{"key":"B13","doi-asserted-by":"publisher","first-page":"57","DOI":"10.1055\/S-2002-25028","article-title":"Treatment of Tourette\u2019s syndrome with \u03949-tetrahydrocannabinol (THC): A randomized crossover trial","volume":"35","author":"M\u00fcller-Vahl","year":"2002","journal-title":"Pharmacopsychiatry"},{"key":"B14","doi-asserted-by":"publisher","DOI":"10.4088\/JCP.V64N0417","article-title":"Delta 9-tetrahydrocannabinol (THC) is effective in the treatment of tics in Tourette syndrome: a 6-week randomized trial","volume":"64","author":"M\u00fcller-Vahl","year":"2003","journal-title":"J Clin Psychiatry"},{"key":"B15","doi-asserted-by":"publisher","first-page":"115135","DOI":"10.1016\/J.PSYCHRES.2023.115135","article-title":"CANNA-TICS: Efficacy and safety of oral treatment with nabiximols in adults with chronic tic disorders - Results of a prospective, multicenter, randomized, double-blind, placebo controlled, phase IIIb superiority study","volume":"323","author":"M\u00fcller-Vahl","year":"2023","journal-title":"Psychiatry Res"},{"key":"B16","doi-asserted-by":"publisher","DOI":"10.1097\/JCP.0B013E3181D236EC","article-title":"Oral delta 9-tetrahydrocannabinol improved refractory Gilles de la Tourette syndrome in an adolescent by increasing intracortical inhibition: a case report","volume":"30","author":"Hasan","year":"2010","journal-title":"J Clin Psychopharmacol"},{"key":"B17","doi-asserted-by":"publisher","first-page":"39","DOI":"10.24911\/EJMCR\/2\/11","article-title":"Delta-9-tetrahydrocannabinol for the treatment of a child with Tourette syndrome - case report","author":"Szejko","year":"2018","journal-title":"Eur J Med Case Rep"},{"key":"B18","doi-asserted-by":"publisher","DOI":"10.1159\/000496355","article-title":"Vaporized cannabis is effective and well-tolerated in an adolescent with tourette syndrome","volume":"2","author":"Szejko","year":"2019","journal-title":"Med Cannabis Cannabinoids"},{"key":"B19","doi-asserted-by":"publisher","first-page":"1739","DOI":"10.3390\/ijms18081739","article-title":"Speechlessness in Gilles de la Tourette Syndrome: Cannabis-based medicines improve severe vocal blocking tics in two patients","volume":"18","author":"Jakubovski","year":"2017","journal-title":"Int J Mol Sci"},{"key":"B20","doi-asserted-by":"publisher","DOI":"10.1097\/00004714-198812000-00021","article-title":"Marijuana and tourette\u2019s syndrome","volume":"8","author":"Sandyk","year":"1988","journal-title":"J Clin Psychopharmacol"},{"key":"B21","doi-asserted-by":"publisher","DOI":"10.1089\/CAN.2024.0188","article-title":"A pilot randomized placebo-controlled crossover trial of medicinal cannabis in adolescents with tourette syndrome","author":"Efron","year":"2025","journal-title":"Cannabis Cannabinoid Res"},{"key":"B22","doi-asserted-by":"publisher","first-page":"293","DOI":"10.1089\/CAN.2022.0112","article-title":"Use of Medical Cannabis in Patients with Gilles de la Tourette\u2019s Syndrome in a Real-World Setting","volume":"9","author":"Barchel","year":"2024","journal-title":"Cannabis Cannabinoid Res"},{"key":"B23","doi-asserted-by":"publisher","first-page":"13","DOI":"10.21037\/PM-20-69","article-title":"A critical narrative review of medical cannabis in pediatrics beyond epilepsy, part II: neurodevelopmental, movement, and pain disorders","volume":"3","author":"Simonian","year":"2020","journal-title":"Pediatr Med"},{"key":"B24","doi-asserted-by":"publisher","DOI":"10.3390\/IJERPH20085430\/S1","article-title":"Medicinal cannabis for paediatric developmental, behavioural and mental health disorders","volume":"20","author":"Efron","year":"2023","journal-title":"Int J Environ Res Public Health"},{"key":"B25","doi-asserted-by":"publisher","DOI":"10.1186\/S13229-021-00420-2","article-title":"Cannabinoid treatment for autism: a proof-of-concept randomized trial","volume":"12","author":"Aran","year":"2021","journal-title":"Mol Autism"},{"key":"B26","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1186\/S13034-024-00846-5\/FIGURES\/3","article-title":"Cannabinoids for treating psychiatric disorders in youth: a systematic review of randomized controlled trials","volume":"18","author":"K\u00f6ck","year":"2024","journal-title":"Child Adolesc Psychiatry Ment Health"},{"key":"B27","doi-asserted-by":"publisher","DOI":"10.3928\/19382359-20230307-04","article-title":"Cannabis toxicity in children and adolescents","volume":"52","author":"George","year":"2023","journal-title":"Pediatr Ann"},{"key":"B28","doi-asserted-by":"publisher","DOI":"10.3390\/BS11030037","article-title":"Cognitive development and cannabis use in adolescents","volume":"11","author":"Frolli","year":"2021","journal-title":"Behav Sci"},{"key":"B29","doi-asserted-by":"publisher","DOI":"10.1001\/jamapsychiatry.2018.0335","article-title":"Association of cannabis with cognitive functioning in adolescents and young adults: A systematic review and meta-analysis","volume":"75","author":"Scott","year":"2018","journal-title":"JAMA Psychiatry"},{"key":"B30","doi-asserted-by":"publisher","first-page":"e2311294","DOI":"10.1001\/JAMANETWORKOPEN.2023.11294","article-title":"Nondisordered cannabis use among US adolescents","volume":"6","author":"Sultan","year":"2023","journal-title":"JAMA Netw Open"},{"key":"B31","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1016\/J.COBEHA.2016.07.001","article-title":"Cognitive motor deficits in cannabis users","volume":"13","author":"Prashad","year":"2017","journal-title":"Curr Opin Behav Sci"},{"key":"B32","doi-asserted-by":"publisher","DOI":"10.1097\/00004583-198907000-00015","article-title":"The yale global tic severity scale: initial testing of a clinician-rated scale of tic severity","volume":"28","author":"Leckman","year":"1989","journal-title":"J Am Acad Child Adolesc Psychiatry"},{"key":"B33","doi-asserted-by":"publisher","DOI":"10.1024\/1422-4917\/A000188","article-title":"Elternversion des Depressions-Inventars f\u00fcr Kinder und Jugendliche (DIKJ) - Befunde zu reliabilit\u00e4t und validit\u00e4t in einer klinischen stichprobe","volume":"40","author":"Weitkamp","year":"2012","journal-title":"Z Kinder Jugendpsychiatr Psychother"},{"key":"B34","doi-asserted-by":"publisher","DOI":"10.1177\/1073191119842255","article-title":"The validity of the SNAP-IV in children displaying ADHD symptoms","volume":"27","author":"Hall","year":"2020","journal-title":"Assessment"},{"key":"B35","doi-asserted-by":"publisher","DOI":"10.1177\/1073191117715731","article-title":"The german version of the perceived stress scale (PSS-10): evaluation of dimensionality, validity, and measurement invariance with exploratory and confirmatory bifactor modeling","volume":"26","author":"Reis","year":"2019","journal-title":"Assessment"},{"key":"B36","doi-asserted-by":"publisher","DOI":"10.1007\/s00787-004-2002-6","article-title":"Normative data and scale properties of the German parent SDQ","volume":"13","author":"Woerner","year":"2004","journal-title":"Eur Child Adolesc Psychiatry Supplement"},{"key":"B37","doi-asserted-by":"publisher","DOI":"10.1212\/01.wnl.0000327890.02893.61","article-title":"The Gilles de la Tourette Syndrome-Quality of Life Scale (GTS-QOL): Development and validation","volume":"71","author":"Cavanna","year":"2008","journal-title":"Neurology"},{"key":"B38","unstructured":"Der Kindl-R Fragebogen zur Erfassung der gesundheitsbezogenen Lebensqualit\u00e4t bei Kindern und Jugendlichen - Revidierte Form"},{"key":"B39","doi-asserted-by":"publisher","first-page":"397","DOI":"10.1097\/00004703-200512000-00001","article-title":"Premonitory urge for tics scale (PUTS)","volume":"26","author":"Woods","year":"2005","journal-title":"J Dev Behav Pediatr"},{"key":"B40","volume-title":"Wechsler Intelligence Scale for Children; manual","author":"Wechsler","year":"1949"},{"key":"B41","doi-asserted-by":"publisher","first-page":"92","DOI":"10.1016\/J.JAAC.2018.05.029","article-title":"Development and psychometric evaluation of the children\u2019s yale-brown obsessive-compulsive scale second edition","volume":"58","author":"Storch","year":"2019","journal-title":"J Am Acad Child Adolesc Psychiatry"},{"key":"B42","doi-asserted-by":"publisher","DOI":"10.3390\/JCM10112479","article-title":"A comprehensive review of tic disorders in children","volume":"10","author":"Ueda","year":"2021","journal-title":"J Clin Med"},{"key":"B43","doi-asserted-by":"publisher","DOI":"10.1007\/S00213-022-06143-3","article-title":"The CannTeen study: verbal episodic memory, spatial working memory, and response inhibition in adolescent and adult cannabis users and age-matched controls","volume":"239","author":"Lawn","year":"2022","journal-title":"Psychopharmacol (Berl)"},{"key":"B44","doi-asserted-by":"publisher","DOI":"10.1177\/08919887211049130","article-title":"Long-term recreational cannabis use is associated with lower executive function and processing speed in a pilot sample of older adults","volume":"35","author":"Stypulkowski","year":"2022","journal-title":"J Geriatr Psychiatry Neurol"},{"key":"B45","doi-asserted-by":"publisher","DOI":"10.1159\/000509377","article-title":"Different effects of cannabis abuse on adolescent and adult brain","volume":"105","author":"Dhein","year":"2020","journal-title":"Pharmacology"},{"key":"B46","doi-asserted-by":"publisher","DOI":"10.3390\/PH17111543","article-title":"The entourage effect in cannabis medicinal products: A comprehensive review","volume":"17","author":"Andr\u00e9","year":"2024","journal-title":"Pharmaceuticals"},{"key":"B47","doi-asserted-by":"publisher","DOI":"10.1089\/CAN.2023.0052","article-title":"Does the \u201cEntourage effect\u201d in cannabinoids exist? A narrative scoping review","volume":"9","author":"Simei","year":"2024","journal-title":"Cannabis Cannabinoid Res"},{"key":"B48","doi-asserted-by":"publisher","DOI":"10.3389\/FPSYT.2022.836908\/BIBTEX","article-title":"Medical cannabis and past-year cannabis use disorder among adult recreational users in the United States: results from a nationally representative sample","volume":"13","author":"Rubin-Kahana","year":"2022","journal-title":"Front Psychiatry"},{"key":"B49","doi-asserted-by":"publisher","first-page":"e2328934","DOI":"10.1001\/JAMANETWORKOPEN.2023.28934","article-title":"Prevalence of cannabis use disorder and reasons for use among adults in a US state where recreational cannabis use is legal","volume":"6","author":"Lapham","year":"2023","journal-title":"JAMA Netw Open"},{"key":"B50","doi-asserted-by":"publisher","DOI":"10.1016\/j.drugalcdep.2024.111263","article-title":"The prevalence of cannabis use disorders in people who use medicinal cannabis: A systematic review and meta-analysis","volume":"257","author":"Dawson","year":"2024","journal-title":"Drug Alcohol Depend"},{"key":"B51","doi-asserted-by":"publisher","first-page":"455","DOI":"10.1370\/AFM.139","article-title":"Physician-patient relationship and medication compliance: A primary care investigation","volume":"2","author":"Kerse","year":"2004","journal-title":"Ann Fam Med"},{"key":"B52","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1038\/S41398-022-02112-8","article-title":"Rates and correlates of cannabis-associated psychotic symptoms in over 230,000 people who use cannabis","volume":"12","author":"Schoeler","year":"2022","journal-title":"Transl Psychiatry"},{"key":"B53","doi-asserted-by":"publisher","DOI":"10.1007\/S00127-019-01810-X","article-title":"Cannabis use in individuals at clinical high-risk for psychosis: a comprehensive review","volume":"55","author":"Farris","year":"2020","journal-title":"Soc Psychiatry Psychiatr Epidemiol"},{"key":"B54","doi-asserted-by":"publisher","DOI":"10.1016\/j.schres.2013.11.014","article-title":"A controlled family study of cannabis users with and without psychosis","volume":"152","author":"Proal","year":"2014","journal-title":"Schizophr Res"},{"key":"B55","doi-asserted-by":"publisher","DOI":"10.1017\/S2045796015000360","article-title":"Adult attention-deficit\/hyperactivity disorder and its association with substance use and substance use disorders in young men","volume":"25","author":"Est\u00e9vez","year":"2016","journal-title":"Epidemiol Psychiatr Sci"},{"key":"B56","doi-asserted-by":"publisher","first-page":"57","DOI":"10.1055\/s-2002-25028","article-title":"Treatment of Tourette\u2019s syndrome with Delta 9-tetrahydrocannabinol (THC): a randomized crossover trial","volume":"35","author":"M\u00fcller-Vahl","year":"2002","journal-title":"Pharmacopsychiatry"},{"key":"B57","doi-asserted-by":"publisher","DOI":"10.1111\/j.1600-0447.1998.tb10127.x","article-title":"Cannabinoids: Possible role in patho-physiology and therapy of Gilles de la Tourette syndrome","volume":"98","author":"Muller-Vahl","year":"1998","journal-title":"Acta Psychiatr Scand"}],"container-title":["Frontiers in Psychiatry"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fpsyt.2025.1647969\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,2]],"date-time":"2025-10-02T08:23:38Z","timestamp":1759393418000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fpsyt.2025.1647969\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,10,2]]},"references-count":57,"alternative-id":["10.3389\/fpsyt.2025.1647969"],"URL":"https:\/\/doi.org\/10.3389\/fpsyt.2025.1647969","relation":{},"ISSN":["1664-0640"],"issn-type":[{"value":"1664-0640","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,10,2]]},"article-number":"1647969"}}