4) Is reduced brain activation in reward anticipation associated with anhedonia in the pre-adolescent stage?
- (Results in "Regression of no. depressive symptoms and anhedonia on MID")
5) If abnormalities in ventral striatal activation to reward anticipation are present in the pre-adolescent stage, are they specific to any domain of psychopathology? In order to do this we used a single regression model with averaged left and right nucleus accumbens reward anticipation as the outcome variable and separate predictor variables of psychotic like experience, depressive symptom score, and anxiety total symptom score, in addition to covariates (age, sex, scanner site, BMI, etc).
- (On reflection I am concerned that this analysis is a little like double-dipping from the previous analyses and may look like an attempt to beat the FDR. All of the results are negative after FDR, but some of which are significant before FDR. A combination approach like the one described might indicate that PPS for example is predictive but other things are not, however we would have previously reported that PPS was not significantly predictive of MID... We might also run in to VIF problems in the regression model where regressors are highly correlated.
- Graham: I see what you say. If anything is significant we would have to report it with considerable caution, agreed - maybe as exploratory and hypothesis generating rather than testing. If its negative it shows we have gone to quite some length to ensure there is a decent shot at detect any small associations and show there is not. I agree multi-colinearity in the predictor variables could be an issue. A lot of the previous work has focussed on the accumbens/ventral striatum so some could argue it merits its own analysis.
Methods
Subjects
A total of 3923 children aged 9-11 years from the ABCD dataset were initially included. These subjects were drawn from 21 centres throughout the US, with participants largely recruited through the school system. Sampling plans and recruitment procedures based on considerations of age, gender, race, socio-economic status and urbanicity were designed to reflect the sociodemographics of the US. Details of recruitment and study design are described elsewhere \cite{Garavan_2018}. Details of demographic, physical and mental health assessments are described elsewhere \citep{Barch_2018}.
Data was taken from the "ABCD1.0 Release" \cite{abcd}. Task imaging data was available for 3179 subjects. Subjects with a diagnosis of ADHD, autism spectrum disorder, schizophrenia and intellectual disability were also excluded from analysis. Subjects who were under-weight as defined by CDC \cite{charts} were also excluded. Subjects were also excluded based on poor task performance. Finally a total of 2129 subjects were ultimately included in the analysis. A breakdown of demographic data is described in Table \ref{421683}.