Liprin alfa 2 gene expression is increased by cannabis use and associated with neuropsychological function.

The relation of heavy cannabis use with decreased neuropsychological function has frequently been described but the underlying biological mechanisms are still largely unknown. This study investigates the relation of cannabis use with genome wide gene expression and subsequently examines the relations with neuropsychological function. Genome-wide gene expression in whole blood was compared between heavy cannabis users (N = 90) and cannabis naïve participants (N = 100) that were matched for psychotic like experiences.

Educational Level, Underachievement, and General Mental Health Problems in 10,866 Adolescents.

Objective: Previous research suggests that cognitive functioning is associated with the risk of several adult psychiatric disorders. In this study we investigated whether adolescents who perform worse than expected at secondary school are at a higher risk for general mental health problems.

Methods: In a cross-sectional survey comprising 10,866 Dutch adolescents aged 13 to 16 years, underachievement at secondary school was defined as the discrepancy between predicted school grade and actual grade 1 or 3 years later.

Delayed school progression and mental health problems in adolescence: a population-based study in 10,803 adolescents.

Background: Accumulating evidence suggests that several adult mental disorders, particularly psychoses, are preceded by impairments in cognitive function, reflected in scholastic underachievement. This study investigates the association between scholastic underachievement and general mental health problems in adolescence, using delay in school progression as a marker of poor scholastic performance.

Method: Cross-sectional secondary school survey comprising 10,803 adolescents.

Does assessment type matter? A measurement invariance analysis of online and paper and pencil assessment of the Community Assessment of Psychic Experiences (CAPE).

Background: The psychometric properties of an online test are not necessarily identical to its paper and pencil original. The aim of this study is to test whether the factor structure of the Community Assessment of Psychic Experiences (CAPE) is measurement invariant with respect to online vs. paper and pencil assessment.

The effect of childhood maltreatment and cannabis use on adult psychotic symptoms is modified by the COMT Val¹⁵⁸Met polymorphism.

Background: Cannabis use and childhood maltreatment are independent risk factors for the development of psychotic symptoms. These factors have been found to interact in some but not all studies. One of the reasons may be that childhood maltreatment and cannabis primarily induce psychotic symptoms in genetically susceptible individuals.

Advanced paternal age and vulnerability to psychotic-like experiences in the offspring.

Objective: To investigate whether advanced paternal age is associated with increased psychotic-like experiences (PLEs) and increased sensitivity to Cannabis in the offspring.

Methods: A cross-sectional population-based study in 1684 participants aged 18 to 25.

Results: We found no association of paternal age with PLEs.

Cannabis use and subclinical positive psychotic experiences in early adolescence: findings from a Dutch survey.

Aims: To investigate the association between early cannabis use and subclinical psychotic experiences, distinguishing between five levels of use: never used, discontinued use (life-time users who did not use in the preceding year), experimental use, regular use and heavy use.

Design: Cross-sectional observational study.

Setting: Dutch Health Behaviour in School-aged Children (HBSC) study, 2005 wave.

Cannabis with high cannabidiol content is associated with fewer psychotic experiences.

Objective: Cannabis is associated with psychotic outcomes in numerous studies, an effect that is commonly attributed to Δ (9)-tetrahydrocannabinol (Δ 9-THC). An increasing number of authors identify cannabidiol, another component of the cannabis plant, as an antipsychotic agent. The objective of the current study is to investigate the role of cannabidiol content in the association between cannabis use and psychiatric symptoms in a large non-clinical population of cannabis users.