Symptoms of Depression but Not Anxiety Modulate Resting State Activity in Children with ASD

Background:

Alterations to resting-state alpha activity have been identified in a number of neuropsychiatric and neurodevelopmental conditions. Previous work from our laboratory showed age-related increases in peak alpha frequency (PAF) in typically developing children (TDC) but not in children with autism spectrum disorder (ASD). Lack of change in the ASD sample was attributable to early maturation of PAF, such that younger (6 to 9-year-old) children with ASD had significantly higher PAF values than TDC. In contrast, older children with ASD had similar or slightly lower PAF values than TDC. Given the literature on alpha activity alterations in individuals with depression and anxiety, as well as high rates of comorbid anxiety/depression in ASD, the present study sought to examine effects of co-occurring anxiety and depression symptoms on resting-state alpha activity in children with ASD.

Objectives:

To explore the association between PAF and clinical symptoms of anxiety/depression in children with ASD.

Methods:

Magnetoencephalography (MEG) resting-state eyes-closed data were obtained from 89 male children with ASD, ages 6 to 17 (mean age = 10.03 +/- 2.42). Using BESA Research 6.1, a source model with 15 regional sources projected the raw MEG surface data into brain source space and a Fast Fourier Transform was applied to artifact-free 3.41 second epochs of continuous data at each regional source. From the 15 average power spectrum, PAF was identified in each participant from the source (most often the midline parietal source) showing the largest amplitude alpha activity (8-12Hz). Clinical measures of interest included parent-rated anxiety and depression symptoms on the Child Behavior Checklist (CBCL) and indices of behavioral regulation and emotional control by parent report on the Behavior Rating Inventory of Executive Function (BRIEF).

Results:

Correlations indicated that higher levels of depression were associated with lower PAF (p = 0.05, r = -0.03). Given known associations between age and PAF, follow-up analyses examined findings in younger (6-9 years) versus older (10-17 years) children. Results indicated a significant negative association between depression symptoms and PAF in younger (p = 0.02, r² = 0.10) but not older ASD children (p = 0.83, r² = 0.002). No associations were observed between PAF and anxiety symptoms (r² = 0.002).

Conclusions:

Increased symptoms of depression were associated with lower PAF values in younger children with ASD, whereas no associations were observed between PAF and anxiety measures. These findings therefore suggest that co-occurring depression symptoms modulate PAF in ASD, altering the anticipated ASD pattern. Further work with larger samples is needed to better understand the effect of mood symptoms on resting-state alpha activity in ASD, with particular focus on younger children, who may be most susceptible to altered alpha activity in the context of symptoms of depression.