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Digital archive of theses discussed at the University of Pisa

 

Thesis etd-10132020-172536


Thesis type
Tesi di specializzazione (4 anni)
Author
NOVI, MARTINA
URN
etd-10132020-172536
Thesis title
Trait and state effects of Substance Use Disorder on brain structure in ADHD patients
Department
MEDICINA CLINICA E SPERIMENTALE
Course of study
PSICHIATRIA
Supervisors
relatore Prof. Perugi, Giulio
relatore Prof. Maremmani, Icro
Keywords
  • attention-deficit/hyperactivity disorder
  • cortical thickness
  • structural imaging
  • subcortical volume
  • substance non-medical use
  • substance use disorder
Graduation session start date
16/11/2020
Availability
Withheld
Release date
16/11/2090
Summary
Several studies separately investigated the neurobiology of Attention Deficit Hyperactivity Disorder (ADHD) and Substance Use Disorder (SUD), showing overlapping morphological abnormalities and suggesting shared pathophysiological mechanisms. Little is known about the combined effect of ADHD and SUD on brain morphology and it is unclear to what extent family history (trait) and/or substance non-medical use (state) effects explain the observed overlap. Our aim was to examine the effects of (i) SUD family history (FH) and (ii) substance non-medical use on brain structure in ADHD population and controls. (iii) We also explored if FH density could have different impact on brain morphology. (i) We investigated SUD trait effects on prefrontal cortical thickness (CT) and subcortical volumes (SCV) in ADHD patients and controls with and without FH (ADHD-FH+: n=139; ADHD-FH-: n=86; controls-FH+: n=60; controls-FH-: n=74). (ii) Then, we tested SUD state effects by comparing FH-matched ADHD patients with and without substance non-medical use and controls (ADHD+SNM, ADHD-only and controls, n=68 per group.(iii) Furthermore, we explored whether FH effects were more pronounced in subjects with SUD in both parents (n=63) compared to subjects with one SUD parent (n=105) and without FH (n=160.(i) Trait analysis revealed that there was no main FH effect on prefrontal CT, while the finding of a bigger putamen in FH+ did not survive after correction for multiple comparisons. (ii) In state analyisis, ADHD+SM showed decreased CT in inferior frontal gyrus (IFG) compared to controls, while no difference was found between ADHD-only and ADHD+SM or controls. We did not find any effect of substance use on subcortical volumes. (iii) Subjects with SUD in both parents showed decreased thickness of IFG and volume of nucleus accumbens (NAcc), compared to those with one SUD parent and those without FH. Substance misuse in ADHD might result in smaller IFG, which is in line with findings in SUD-literature. Greater SUD FH density suggests premorbid alterations in inhibitory control and reward networks. Future studies should investigate the potential role of these regions in term of treatment and prevention strategies.
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