O9.6. SYSTEMATIC REVIEW AND META-ANALYSIS OF THE EFFECTS OF CANNABIS USE IN ADOLESCENCE ON IQ IN LONGITUDINAL STUDIES ACCOUNTING PRE-EXPOSURE BASELINE PERFORMANCE
Notice bibliographique
Résumé
Abstract Background Cannabis use in adolescence is a known risk factor for developing schizophrenia. Decline in intellectual functioning is a well-studied phenomenon of schizophrenia. Schizophrenia in its first classification was conceptualized as a dementia - ‘Dementia Praecox’ indicating a dominance of effect of cognitive symptoms on functioning at that time. First episode psychosis patients with histories of cannabis use compared to those without cannabis use have superior cognitive functioning suggesting different disease phenotypes. Our aim was to investigate whether cannabis had an effect on full scale IQ in general population samples to further inform understanding of this disease pathway. Methods We developed a search strategy through an iterative approach with a qualified information specialist. We searched three databases: Medline, Embase and PsychInfo. We included conference abstracts and full text publications in English. We contacted authors for additional information in cases where an effect size was not calculable. We included longitudinal studies of non-help-seeking young people in the community with a pre-drug exposure standardized measure of IQ prior to the age of 18 and a comparable measure at subsequent follow up. We defined the case group as individuals with a history of heavy cannabis use (more than 25 lifetime uses, at least weekly use for 6 months and/or meeting criteria for a cannabis use disorder) and the control group as similar young people who had no or very minimal experimental exposure to cannabis (<5 lifetime uses). Two reviewers independently extracted the data and assessed for bias using the Newcastle-Ottawa risk of bias tool. We performed random effects meta-analysis in Stata version 14 given expected heterogeneity in measurement of cannabis use across studies. Results We identified 7 cohort studies detailed in 6 reports including over 650 subjects and 5600 controls. Study designs included twin cohorts, representative cluster sampled community cohorts and birth cohort studies. Range of follow up was between 2 and 23 years. All studies showed relative decline in IQ of which two were statistically significant. Our findings show that cannabis use in youth is associated with modest IQ differences that equate to approximately to a 2-point decrease in young cannabis users. Studies examining twin pairs showed that twins discordant for cannabis use did not have divergent cognitive trajectories, however these analyses were relatively underpowered to find an effect. Discussion Our findings demonstrate the harmful effects of cannabis use on brain development in young people. These findings are of public health importance and provide further evidence for the detrimental effects of early cannabis use on mental health and cognition.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,019 | 0,057 |
| Méta-épidémiologie (sens strict) | 0,003 | 0,002 |
| Méta-épidémiologie (sens large) | 0,021 | 0,032 |
| Bibliométrie | 0,010 | 0,011 |
| Études des sciences et des technologies | 0,001 | 0,001 |
| Communication savante | 0,005 | 0,003 |
| Science ouverte | 0,003 | 0,002 |
| Intégrité de la recherche | 0,003 | 0,002 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,011 | 0,001 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».