Neuropsychological consequences of regular marijuana use: a twin study.

Saved in:
Bibliographic Details
Title: Neuropsychological consequences of regular marijuana use: a twin study.
Authors: Lyons MJ (AUTHOR), Bar JL (AUTHOR), Panizzon MS (AUTHOR), Toomey R (AUTHOR), Eisen S (AUTHOR), Xian H (AUTHOR), Tsuang MT (AUTHOR)
Source: Psychological Medicine. Oct2004, Vol. 34 Issue 7, p1239-1250. 12p.
Abstract: BACKGROUND: Results of previous research examining long-term residual effects of marijuana use on cognition are conflicting. A major methodological limitation of prior studies is the inability to determine whether differences between users and non-users are due to differences in genetic vulnerability preceding drug use or due to the effects of the drug. METHOD: Fifty-four monozygotic male twin pairs, discordant for regular marijuana use in which neither twin used any other illicit drug regularly, were recruited from the Vietnam Era Twin Registry. A minimum of 1 year had passed since the marijuana-using twins had last used the drug, and a mean of almost 20 years had passed since the last time marijuana had been used regularly. Twins were administered a comprehensive neuropsychological test battery to assess general intelligence, executive functioning, attention, memory and motor skills. Differences in performance between marijuana-using twins and their non-using co-twins were compared using a multivariate analysis of specific cognitive domains and univariate analyses of individual test scores. Dose response relationships were explored within the marijuana-using group. RESULTS: Marijuana-using twins significantly differed from their non-using co-twins on the general intelligence domain; however, within that domain only the performance of the block design subtest of the Wechsler Adult Intelligence Scale--Revised reached a level of statistical significance. CONCLUSIONS: Out of the numerous measures that were administered, only one significant difference was noted between marijuana-using twins and their non-using co-twins on cognitive functioning. The results indicate an absence of marked long-term residual effects of marijuana use on cognitive abilities. [ABSTRACT FROM AUTHOR]
Copyright of Psychological Medicine is the property of Cambridge University Press and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Database: Psychology and Behavioral Sciences Collection
FullText Text:
  Availability: 0
Header DbId: pbh
DbLabel: Psychology and Behavioral Sciences Collection
An: 106595760
AccessLevel: 6
PubType: Academic Journal
PubTypeId: academicJournal
PreciseRelevancyScore: 0
IllustrationInfo
Items – Name: Title
  Label: Title
  Group: Ti
  Data: Neuropsychological consequences of regular marijuana use: a twin study.
– Name: Author
  Label: Authors
  Group: Au
  Data: <searchLink fieldCode="AR" term="%22Lyons+MJ%22">Lyons MJ</searchLink> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Bar+JL%22">Bar JL</searchLink> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Panizzon+MS%22">Panizzon MS</searchLink> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Toomey+R%22">Toomey R</searchLink> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Eisen+S%22">Eisen S</searchLink> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Xian+H%22">Xian H</searchLink> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Tsuang+MT%22">Tsuang MT</searchLink> (AUTHOR)
– Name: TitleSource
  Label: Source
  Group: Src
  Data: <searchLink fieldCode="JN" term="%22Psychological+Medicine%22">Psychological Medicine</searchLink>. Oct2004, Vol. 34 Issue 7, p1239-1250. 12p.
– Name: Abstract
  Label: Abstract
  Group: Ab
  Data: BACKGROUND: Results of previous research examining long-term residual effects of marijuana use on cognition are conflicting. A major methodological limitation of prior studies is the inability to determine whether differences between users and non-users are due to differences in genetic vulnerability preceding drug use or due to the effects of the drug. METHOD: Fifty-four monozygotic male twin pairs, discordant for regular marijuana use in which neither twin used any other illicit drug regularly, were recruited from the Vietnam Era Twin Registry. A minimum of 1 year had passed since the marijuana-using twins had last used the drug, and a mean of almost 20 years had passed since the last time marijuana had been used regularly. Twins were administered a comprehensive neuropsychological test battery to assess general intelligence, executive functioning, attention, memory and motor skills. Differences in performance between marijuana-using twins and their non-using co-twins were compared using a multivariate analysis of specific cognitive domains and univariate analyses of individual test scores. Dose response relationships were explored within the marijuana-using group. RESULTS: Marijuana-using twins significantly differed from their non-using co-twins on the general intelligence domain; however, within that domain only the performance of the block design subtest of the Wechsler Adult Intelligence Scale--Revised reached a level of statistical significance. CONCLUSIONS: Out of the numerous measures that were administered, only one significant difference was noted between marijuana-using twins and their non-using co-twins on cognitive functioning. The results indicate an absence of marked long-term residual effects of marijuana use on cognitive abilities. [ABSTRACT FROM AUTHOR]
– Name: AbstractSuppliedCopyright
  Label:
  Group: Ab
  Data: <i>Copyright of Psychological Medicine is the property of Cambridge University Press and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.)
PLink https://search.ebscohost.com/login.aspx?direct=true&site=eds-live&db=pbh&AN=106595760
RecordInfo BibRecord:
  BibEntity:
    Identifiers:
      – Type: doi
        Value: 10.1017/s0033291704002260
    Languages:
      – Code: eng
        Text: English
    PhysicalDescription:
      Pagination:
        PageCount: 12
        StartPage: 1239
    Titles:
      – TitleFull: Neuropsychological consequences of regular marijuana use: a twin study.
        Type: main
  BibRelationships:
    HasContributorRelationships:
      – PersonEntity:
          Name:
            NameFull: Lyons MJ
      – PersonEntity:
          Name:
            NameFull: Bar JL
      – PersonEntity:
          Name:
            NameFull: Panizzon MS
      – PersonEntity:
          Name:
            NameFull: Toomey R
      – PersonEntity:
          Name:
            NameFull: Eisen S
      – PersonEntity:
          Name:
            NameFull: Xian H
      – PersonEntity:
          Name:
            NameFull: Tsuang MT
    IsPartOfRelationships:
      – BibEntity:
          Dates:
            – D: 01
              M: 10
              Text: Oct2004
              Type: published
              Y: 2004
          Identifiers:
            – Type: issn-print
              Value: 00332917
          Numbering:
            – Type: volume
              Value: 34
            – Type: issue
              Value: 7
          Titles:
            – TitleFull: Psychological Medicine
              Type: main
ResultId 1