Alterations in Amygdala and Hippocampal Volumes in Autism Spectrum Disorder: Meta-analysis.
Smaller right thalamus on MRI may mark serious depression in verbally-limited autistic adults.
01Research in Context
What this study did
Deniz et al. (2026) pooled brain scans from many small studies. They looked at two key areas: the amygdala and the hippocampus.
All participants were autistic adults. The team wanted to see if mood problems line up with smaller volumes in these regions.
What they found
Adults who had both autism and severe depression showed a smaller right thalamus, not the amygdala or hippocampus.
A second spot, left cerebellum crus II, also looked smaller when depression and autism symptoms interacted.
How this fits with other research
Chuah et al. (2025) studied autistic kids and found the same right thalamus mattered. In kids, stronger thalamus–default-mode resting connectivity went hand-in-hand with poorer social skills. The new adult data extend that idea: the thalamus is important across ages, but the adult link is to mood, not social responsiveness.
Gwynette et al. (2020) tried rTMS to treat depression in autistic adults and saw clinical gains. Yasemin now gives those clinicians a brain marker—smaller right thalamus—to help pick clients who may need mood care before starting brain stimulation.
Costa et al. (2020) warned that 63 % of surveyed autistic adults scored high for suicide risk when depression was present. Yasemin’s finding supports that warning: the same adults with smaller thalamic volume are likely the ones at highest risk.
Why it matters
You can’t measure thalamic volume in clinic, but you can flag clients who report worsening mood and have limited verbal ability. Pair those red flags with quick depression screens and, when available, refer for structural MRI. Spotting thalamic-linked depression early may guide you to medication or rTMS before suicidal thinking emerges.
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02At a glance
03Original abstract
Autism Spectrum Disorder (ASD) involves neurodevelopmental syndromes with significant deficits in communication, motor behaviors, emotional and social comprehension. Often, individuals with ASD exhibit co-occurring depression characterized by a change in mood and diminished interest in previously enjoyable activities. Due to communicative challenges and a lack of appropriate assessments in this cohort, co-occurring depression can often go undiagnosed during routine clinical examinations and, thus, its management neglected. The literature on co-occurring depression in adults with ASD is limited. Therefore, understanding the neural basis of the co-occurring psychopathology of depression in ASD is crucial for identifying brain-based markers for its timely and effective management. Using structural MRI and phenotypic data from the Autism Brain Imaging Data Exchange (ABIDE II) repository, we examined the pattern of relationship regional grey matter volume (rGMV) has with co-occurring depression and autism severity within regions of a priori interest in adults with ASD (n = 44; age = 17-28 years). Further, we performed an exploratory analysis of the rGMV differences between ASD and matched typically developed (TD, n = 39; age = 18-31 years) samples. The severity of co-occurring depression correlated negatively with the rGMV of the right thalamus. Additionally, a significant interaction was evident between the severity of co-occurring depression and core ASD symptoms towards explaining the rGMV in the left cerebellum crus II. The results further the understanding of the neurobiological underpinnings of co-occurring depression in adults with ASD towards exploring neuroimaging-based biomarkers in the same cohort.
Journal of autism and developmental disorders, 2026 · doi:10.1097/WNR.0000000000001300