Cannabis abstinence and thinking skills in 15–18-year-olds

Cannabis Abstinence and Neurocognitive Assessment in Adolescence

Observational University Hospital Pilsen · NCT07160153

We will test whether stopping cannabis use leads to improved thinking and memory in 15–18-year-olds with cannabis dependence or harmful use, with abstinence verified by urine tests.

Quick facts

Study typeObservational
Enrollment29 (estimated)
Ages15 Years to 18 Years
SexAll
SponsorUniversity Hospital Pilsen Academic / other
Locations1 site (Pilsen, Czechia)
Trial IDNCT07160153 on ClinicalTrials.gov

What this trial studies

This observational study follows adolescents aged 15–18 who have cannabis dependence or harmful cannabis use and measures neurocognitive function before and after confirmed abstinence. Participants undergo standardized neuropsychological testing and urine toxicology to verify abstinence between assessments. The study excludes those with major psychiatric disorders (except stabilized anxiety), severe somatic illnesses, or those who violate abstinence or require major medication changes. Psychotropic medications are allowed except antipsychotics for psychosis, and all testing is conducted at a single hospital site in Pilsen, Czechia.

Who should consider this trial

Good fit: Adolescents aged 15–18 diagnosed with cannabis dependence or harmful cannabis use who can provide urine-confirmed abstinence and do not have excluded psychiatric or severe somatic comorbidities are ideal candidates.

Not a fit: Patients with dual diagnoses such as psychotic or severe mood disorders, major organic brain damage, autism spectrum disorder, severe somatic disease, or those unable to maintain abstinence are unlikely to benefit from this protocol.

Why it matters

Potential benefit: If successful, the results could clarify whether cognitive functions recover after cannabis abstinence in adolescents and help guide timing and focus of treatments.

How similar studies have performed: Prior research has shown mixed but promising evidence that some cognitive deficits after cannabis use can improve with sustained abstinence, so this study builds on but does not radically depart from existing findings.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Adolescents aged 15-18 years with a diagnosis of cannabis dependence or harmful cannabis use.

Exclusion Criteria:

* psychiatric comorbidity - Dual diagnosis, including psychotic disorders, mood disorders, severe organic brain damage, or autism spectrum disorder, with the exception of compensated and stabilized anxiety disorder. Psychopharmacological treatment is permitted, except for antipsychotics prescribed for psychosis.
* somatic comorbidity - Severe endocrine disorders such as diabetes mellitus, thyroid dysfunction, or severe cardiovascular disease.
* Violation of abstinence between the first and second neuropsychological assessments, as well as severe decompensation of mental state requiring modification of established psychopharmacological treatment.

Where this trial is running

Pilsen, Czechia

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Cannabis DependenceHarmful UseCognitive AssessmentCannabis Use DisorderAbstinenceCognitive FunctionDisorderNeuropsychological
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.