Madeline H Meier1, Avshalom Caspi1, Annchen R Knodt1, Wayne Hall1, Antony Ambler1, HonaLee Harrington1, Sean Hogan1, Renate M Houts1, Richie Poulton1, Sandhya Ramrakha1, Ahmad R Hariri1, Terrie E Moffitt1. 1. Department of Psychology, Arizona State University, Tempe (Meier); Department of Psychology and Neuroscience (Caspi, Knodt, Harrington, Houts, Hariri, Moffitt) and Department of Psychiatry and Behavioral Sciences (Caspi, Moffitt), Duke University, Durham, N.C.; Institute of Psychiatry, Psychology, and Neuroscience, King's College London (Caspi, Ambler, Moffitt); Centre for Youth Substance Abuse Research, University of Queensland, St Lucia, Australia (Hall); Dunedin Multidisciplinary Health and Development Research Unit, Department of Psychology, University of Otago, Dunedin, New Zealand (Ambler, Hogan, Poulton, Ramrakha).
Abstract
OBJECTIVE: Cannabis use is increasing among midlife and older adults. This study tested the hypotheses that long-term cannabis use is associated with cognitive deficits and smaller hippocampal volume in midlife, which is important because midlife cognitive deficits and smaller hippocampal volume are risk factors for dementia. METHODS: Participants are members of a representative cohort of 1,037 individuals born in Dunedin, New Zealand, in 1972-1973 and followed to age 45, with 94% retention. Cannabis use and dependence were assessed at ages 18, 21, 26, 32, 38, and 45. IQ was assessed at ages 7, 9, 11, and 45. Specific neuropsychological functions and hippocampal volume were assessed at age 45. RESULTS: Long-term cannabis users showed IQ decline from childhood to midlife (mean=-5.5 IQ points), poorer learning and processing speed relative to their childhood IQ, and informant-reported memory and attention problems. These deficits were specific to long-term cannabis users because they were either not present or were smaller among long-term tobacco users, long-term alcohol users, midlife recreational cannabis users, and cannabis quitters. Cognitive deficits among long-term cannabis users could not be explained by persistent tobacco, alcohol, or other illicit drug use, childhood socioeconomic status, low childhood self-control, or family history of substance dependence. Long-term cannabis users showed smaller hippocampal volume, but smaller hippocampal volume did not statistically mediate cannabis-related cognitive deficits. CONCLUSIONS: Long-term cannabis users showed cognitive deficits and smaller hippocampal volume in midlife. Research is needed to ascertain whether long-term cannabis users show elevated rates of dementia in later life.
OBJECTIVE: Cannabis use is increasing among midlife and older adults. This study tested the hypotheses that long-term cannabis use is associated with cognitive deficits and smaller hippocampal volume in midlife, which is important because midlife cognitive deficits and smaller hippocampal volume are risk factors for dementia. METHODS: Participants are members of a representative cohort of 1,037 individuals born in Dunedin, New Zealand, in 1972-1973 and followed to age 45, with 94% retention. Cannabis use and dependence were assessed at ages 18, 21, 26, 32, 38, and 45. IQ was assessed at ages 7, 9, 11, and 45. Specific neuropsychological functions and hippocampal volume were assessed at age 45. RESULTS: Long-term cannabis users showed IQ decline from childhood to midlife (mean=-5.5 IQ points), poorer learning and processing speed relative to their childhood IQ, and informant-reported memory and attention problems. These deficits were specific to long-term cannabis users because they were either not present or were smaller among long-term tobacco users, long-term alcohol users, midlife recreational cannabis users, and cannabis quitters. Cognitive deficits among long-term cannabis users could not be explained by persistent tobacco, alcohol, or other illicit drug use, childhood socioeconomic status, low childhood self-control, or family history of substance dependence. Long-term cannabis users showed smaller hippocampal volume, but smaller hippocampal volume did not statistically mediate cannabis-related cognitive deficits. CONCLUSIONS: Long-term cannabis users showed cognitive deficits and smaller hippocampal volume in midlife. Research is needed to ascertain whether long-term cannabis users show elevated rates of dementia in later life.
Entities:
Keywords:
Cannabis; Cognition/Learning/Memory; Neuroimaging; Substance-Related and Addictive Disorders
Authors: Madeline H Meier; Avshalom Caspi; Antony Ambler; HonaLee Harrington; Renate Houts; Richard S E Keefe; Kay McDonald; Aimee Ward; Richie Poulton; Terrie E Moffitt Journal: Proc Natl Acad Sci U S A Date: 2012-08-27 Impact factor: 11.205
Authors: Nadia Solowij; Robert S Stephens; Roger A Roffman; Thomas Babor; Ronald Kadden; Michael Miller; Kenneth Christiansen; Bonnie McRee; Janice Vendetti Journal: JAMA Date: 2002-03-06 Impact factor: 56.272
Authors: Reto Auer; Eric Vittinghoff; Kristine Yaffe; Arnaud Künzi; Stefan G Kertesz; Deborah A Levine; Emiliano Albanese; Rachel A Whitmer; David R Jacobs; Stephen Sidney; M Maria Glymour; Mark J Pletcher Journal: JAMA Intern Med Date: 2016-03 Impact factor: 44.409