title: Frontal white matter changes and aggression in methamphetamine dependence.
abstract: Chronic methamphetamine (MA) use can lead to white matter (WM) changes and increased levels of aggression. While previous studies have examined WM abnormalities relating to cognitive impairment, associations between WM integrity and aggression in MA dependence remain unclear. Diffusion Tensor Imaging (DTI) was used to investigate WM changes in 40 individuals with MA dependence and 40 matched healthy controls. A region of interest (ROI) approach using tract based spatial statistics (TBSS) in FSL was performed. We compared fractional anisotropy (FA), mean diffusivity (MD), parallel diffusivity (λ║) and perpendicular diffusivity (λ┴) in WM tracts of the frontal brain. A relationship of WM with aggression scores from the Buss & Perry Questionnaire was investigated. Mean scores for anger (p < 0.001), physical aggression (p = 0.032) and total aggression (p = 0.021) were significantly higher in the MA group relative to controls. ROI analysis showed increased MD (U = 439.5, p = 0.001) and λ┴ (U = 561.5, p = 0.021) values in the genu of the corpus callosum, and increased MD (U = 541.5, p = 0.012) values in the right cingulum in MA dependence. None of the WM changes were significantly associated with aggression scores. This study provides evidence of frontal WM changes and increased levels of aggression in individuals with MA dependence. The lack of significant associations between WM and aggressive behaviour may reflect methodological issues in measuring such behaviour, or may indicate that the neurobiology of aggression is not simply correlated with WM damage but is more complex.
authors.affiliation: Department of Psychiatry and Mental Health, University of Cape Town, J-Block, Groote Schuur Hospital, Observatory, South Africa.
authors.forename: Katharina
authors.initials: K
authors.lastname: Lederer
authors.affiliation: Department of Psychiatry and Mental Health, University of Cape Town, J-Block, Groote Schuur Hospital, Observatory, South Africa.|Department of Psychiatry, University of Stellenbosch, Cape Town, South Africa.
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Fouche
authors.affiliation: Department of Psychiatry and Mental Health, University of Cape Town, J-Block, Groote Schuur Hospital, Observatory, South Africa.
authors.forename: Don
authors.initials: D
authors.lastname: Wilson
authors.affiliation: Department of Psychiatry and Mental Health, University of Cape Town, J-Block, Groote Schuur Hospital, Observatory, South Africa.
authors.forename: Dan J
authors.initials: DJ
authors.lastname: Stein
authors.affiliation: Department of Psychiatry and Mental Health, University of Cape Town, J-Block, Groote Schuur Hospital, Observatory, South Africa. uhlmann.aa@gmail.com.
authors.forename: Anne
authors.identifier: http://orcid.org/0000-0002-1753-7811
authors.initials: A
authors.lastname: Uhlmann
mesh_terms: D000293:Adolescent; D000328:Adult; D000374:Aggression / Q000187:drug effects / Q000523:psychology*; D019969:Amphetamine-Related Disorders / Q000473:pathology* / Q000523:psychology*; D000786:Anger / Q000187:drug effects; D000697:Central Nervous System Stimulants; D003337:Corpus Callosum / Q000473:pathology; D039721:Diagnostic and Statistical Manual of Mental Disorders; D056324:Diffusion Tensor Imaging; D005260:Female; D005625:Frontal Lobe / Q000187:drug effects / Q000473:pathology*; D006801:Humans; D008297:Male; D008694:Methamphetamine; D066127:White Matter / Q000187:drug effects / Q000473:pathology*; D055815:Young Adult
chemical_list: D000697:Central Nervous System Stimulants; D008694:Methamphetamine
keywords: Diffusion tensor imaging; Diffusivity; Fractional anisotropy; Microstructure; Stimulants