Cannabis use and childhood trauma interact additively to increase the risk of psychotic symptoms in adolescence

Abstract

BackgroundAdolescent cannabis use has been shown in many studies to increase the risk of later psychosis. Childhood trauma is associated with both substance misuse and risk for psychosis. In this study our aim was to investigate whether there is a significant interaction between cannabis use and childhood trauma in increasing the risk for experiencing psychotic symptoms during adolescence.MethodPsychiatric interviews using the Schedule for Affective Disorders and Schizophrenia for School-Age Children (K-SADS) semi-structured instrument were carried out with 211 adolescents aged between 12 and 15 years and their parents as part of a population-based study. The interview enquired about early traumatic events, cannabis use and psychiatric symptoms in adolescence.ResultsIn separate analyses both cannabis use and childhood trauma were significantly associated with risk of experiencing psychotic symptoms. However, the presence of both childhood trauma and early cannabis use significantly increased the risk for psychotic symptoms beyond the risk posed by either risk factor alone, indicating that there was a greater than additive interaction between childhood trauma and cannabis use.ConclusionOur finding of a greater than additive interaction between childhood trauma and cannabis use may have implications for the identification of individuals at high risk of experiencing psychotic symptoms. For example, measures to actively discourage or intensively treat cannabis use in children and adolescents who have experienced abuse may help to prevent the development of psychosis in this vulnerable group. Our findings require replication in larger samples to confirm this interaction effect.

Predicting Risk and the Emergence of Schizophrenia

“…Recent evidence has shown that childhood trauma is a risk factor for the development of schizophrenia [42][43][44] and psychotic symptoms. 45 Although several previous studies have suffered from methodological limitations, such as small, highly selected samples and nonstandardized measures of trauma, a recent study has sought to overcome these problems.…”

“…44 Both cannabis use and childhood trauma, however, additively interacted to increase the likelihood of psychotic symptoms in adolescence to a much greater extent than either risk factor independently. This indication of environmental factors working together to produce a synergistic effect on risk has been found in other studies.…”

Experiencias psicóticas atenuadas y consumo de sustancias en universitarios

“…Por ejemplo, estudios epidemiológicos han encontrado que la iniciación en el uso de cannabis en la adolescencia incrementa la probabilidad de síntomas y trastornos psicóticos en la edad adulta (Arseneault et al, 2002) y favorece su persistencia en el tiempo (Mackie et al, 2013). Del mismo modo, parece ser que si el consumo de cannabis interactúa con otros factores de riesgo como son las experiencias traumáticas, aumenta la probabilidad de presencia de síntomas psicóticos (Cougnard et al, 2007;Harley et al, 2010). Otros modelos, basados en estudios animales, también postulan sobre el efecto que los cannabinoides puedan ocasionar en diferentes receptores dopaminérgicos y/o cannabinoides (especialmente a nivel del córtex prefrontal, estriado e hipocampo), así como acerca de su capacidad de generar modificaciones en el sistema glutamatérgico e inducir una cascada de cambios bioquími-cos, tal vez neurotóxicos, y de igual forma, incrementando el riesgo de desarrollar trastornos psicóticos (Bossong y Niesink, 2010;Rocchetti et al, 2013).…”

Cannabinoids and Schizophrenia: Risks and Therapeutic Potential

“…Another population registry-based study found that family history of schizophrenia increased both the risk of schizophrenia and of acute cannabis-induced psychosis [25]. A history of child abuse (including sexual, physical, and/or emotional abuse) or neglect also increases the risk of developing schizophrenia after cannabis use [26][27][28][29][30][31]. Two large, population-based, longitudinal studies, in Greece and the Netherlands, both replicated findings that childhood maltreatment and cannabis use precede and are independently associated with increased risk of later psychosis, and that the combination of the 2 risk factors is synergistically associated with an increased risk of psychosis [28].…”