American Psychiatric Association. Diagnostic and statistical manual of mental disorders. 5th ed. Arlington, VA: American Psychiatric Association; 2013.

Maenner MJ, Warren Z, Williams AR, Amoakohene E, Bakian AV, Bilder DA, et al. Prevalence and characteristics of autism spectrum disorder among children aged 8 years—autism and developmental disabilities monitoring network, 11 sites, United States, 2020. MMWR Surveill Summ. 2023;72:1–14.

Article  PubMed  PubMed Central  Google Scholar 

Bourson L, Prevost C. Characteristics of restricted interests in girls with ASD compared to boys: a systematic review of the literature. Eur Child Adolesc Psychiatry. 2022. https://doi.org/10.1007/s00787-022-01998-5

Lai MC, Lombardo MV, Auyeung B, Chakrabarti B, Baron-Cohen S. Sex/gender differences and autism: setting the scene for future research. J Am Acad Child Adolesc Psychiatry. 2015;54:11–24.

Article  PubMed  PubMed Central  Google Scholar 

Mo K, Sadoway T, Bonato S, Ameis SH, Anagnostou E, Lerch JP, et al. Sex/gender differences in the human autistic brains: a systematic review of 20 years of neuroimaging research. Neuroimage Clin. 2021;32:102811.

Article  PubMed  PubMed Central  Google Scholar 

Rossignol DA, Frye RE. Mitochondrial dysfunction in autism spectrum disorders: a systematic review and meta-analysis. Mol Psychiatry. 2012;17:290–314.

Article  CAS  PubMed  Google Scholar 

Masi A, Quintana DS, Glozier N, Lloyd AR, Hickie IB, Guastella AJ. Cytokine aberrations in autism spectrum disorder: a systematic review and meta-analysis. Mol Psychiatry. 2015;20:440–6.

Article  CAS  PubMed  Google Scholar 

Al-Haddad BJS, Jacobsson B, Chabra S, Modzelewska D, Olson EM, Bernier R, et al. Long-term risk of neuropsychiatric disease after exposure to infection in utero. JAMA Psychiatry. 2019;76:594–602.

Article  PubMed  PubMed Central  Google Scholar 

Tang G, Gutierrez Rios P, Kuo SH, Akman HO, Rosoklija G, Tanji K, et al. Mitochondrial abnormalities in temporal lobe of autistic brain. Neurobiol Dis. 2013;54:349–61.

Article  CAS  PubMed  PubMed Central  Google Scholar 

Gupta S, Ellis SE, Ashar FN, Moes A, Bader JS, Zhan J, et al. Transcriptome analysis reveals dysregulation of innate immune response genes and neuronal activity-dependent genes in autism. Nat Commun. 2014;5:5748.

Article  CAS  PubMed  Google Scholar 

Werling DM, Parikshak NN, Geschwind DH. Gene expression in human brain implicates sexually dimorphic pathways in autism spectrum disorders. Nat Commun. 2016;7:10717.

Article  CAS  PubMed  PubMed Central  Google Scholar 

Silaidos C, Pilatus U, Grewal R, Matura S, Lienerth B, Pantel J, et al. Sex-associated differences in mitochondrial function in human peripheral blood mononuclear cells (PBMCs) and brain. Biol Sex Differ. 2018;9:34.

Article  CAS  PubMed  PubMed Central  Google Scholar 

Anitha A, Nakamura K, Thanseem I, Matsuzaki H, Miyachi T, Tsujii M, et al. Downregulation of the expression of mitochondrial electron transport complex genes in autism brains. Brain Pathol. 2013;23:294–302.

Article  PubMed  Google Scholar 

Notter T, Coughlin JM, Gschwind T, Weber-Stadlbauer U, Wang Y, Kassiou M, et al. Translational evaluation of translocator protein as a marker of neuroinflammation in schizophrenia. Mol Psychiatry. 2018;23:323–34.

Article  CAS  PubMed  Google Scholar 

Zürcher NR, Loggia ML, Mullett JE, Tseng C, Bhanot A, Richey L, et al. [(11)C]PBR28 MR–PET imaging reveals lower regional brain expression of translocator protein (TSPO) in young adult males with autism spectrum disorder. Mol Psychiatry. 2021;26:1659–69.

Article  PubMed  Google Scholar 

Suzuki K, Sugihara G, Ouchi Y, Nakamura K, Futatsubashi M, Takebayashi K, et al. Microglial activation in young adults with autism spectrum disorder. JAMA Psychiatry. 2013;70:49–58.

Article  PubMed  Google Scholar 

Simpson D, Gharehgazlou A, Da Silva T, Labrie-Cleary C, Wilson AA, Meyer JH, et al. In vivo imaging translocator protein (TSPO) in autism spectrum disorder. Neuropsychopharmacology. 2022;47:1421–7.

Article  CAS  PubMed  PubMed Central  Google Scholar 

Kreisl WC, Fujita M, Fujimura Y, Kimura N, Jenko KJ, Kannan P, et al. Comparison of [(11)C]-(R)-PK 11195 and [(11)C]PBR28, two radioligands for translocator protein (18 kDa) in human and monkey: implications for positron emission tomographic imaging of this inflammation biomarker. Neuroimage. 2010;49:2924–32.

Article  CAS  PubMed  Google Scholar 

Kato Y, Yokokura M, Iwabuchi T, Murayama C, Harada T, Goto T, et al. Lower availability of mitochondrial complex I in anterior cingulate cortex in autism: a positron emission tomography study. Am J Psychiatry. 2023;180:277–284.

Jack A, Pelphrey KA. Annual Research Review: understudied populations within the autism spectrum – current trends and future directions in neuroimaging research. J Child Psychol Psychiatry. 2017;58:411–35.

Article  PubMed  PubMed Central  Google Scholar 

Kalk NJ, Owen DR, Tyacke RJ, Reynolds R, Rabiner EA, Lingford-Hughes AR, et al. Are prescribed benzodiazepines likely to affect the availability of the 18 kDa translocator protein (TSPO) in PET studies? Synapse. 2013;67:909–12.

Article  CAS  PubMed  Google Scholar 

Roid G. Stanford-Binet Intelligence Scales. 5th ed. Itasca, IL: Riverside Publishing; 2003.

Gershen LD, Zanotti-Fregonara P, Dustin IH, Liow J-S, Hirvonen J, Kreisl WC, et al. Neuroinflammation in temporal lobe epilepsy measured using positron emission tomographic imaging of translocator protein. JAMA Neurol. 2015;72:882–8.

Article  PubMed  PubMed Central  Google Scholar 

Owen DR, Yeo AJ, Gunn RN, Song K, Wadsworth G, Lewis A, et al. An 18-kDa translocator protein (TSPO) polymorphism explains differences in binding affinity of the PET radioligand PBR28. J Cereb Blood Flow Metab. 2012;32:1–5.

Article  CAS  PubMed  Google Scholar 

Lord C, Rutter M, Le Couteur A. AutIsm Diagnostic Interview – Revised: a revised version of a diagnostic interview for caregivers of individuals with possible pervasive developmental disorders. J Autism Dev Disord. 1994;24:659–85.

Article  CAS  PubMed  Google Scholar 

Rutter M, Le Couteur A, Lord C. Autism Diagnostic Interview – Revised. Los Angeles, CA: Western Psychological Services; 2003.

Lord C, Rutter M, DiLavore PC, Risi S, Gotham K, Bishop S. Autism Diagnostic Observation Schedule, 2nd ed. (ADOS-2). Los Angeles, CA: Western Psychological Services; 2012.

Hus V, Lord C. The autism diagnostic observation schedule, module 4: revised algorithm and standardized severity scores. J Autism Dev Disord. 2014;44:1996–2012.

Article  PubMed  PubMed Central  Google Scholar 

Morrier MJ, Ousley OY, Caceres-Gamundi GA, Segall MJ, Cubells JF, Young LJ, et al. Brief report: relationship between ADOS-2, module 4 calibrated severity scores (CSS) and social and non-social standardized assessment measures in adult males with autism spectrum disorder (ASD). J Autism Dev Disord. 2017;47:4018–24.

Article  PubMed  PubMed Central  Google Scholar 

Smith CJ, Bhanot A, Norman E, Mullett JE, Bilbo SD, McDougle CJ, et al. A protocol for sedation free MRI and PET imaging in adults with autism spectrum disorder. J Autism Dev Disord. 2019;49:3036–44.

Article  CAS  PubMed  Google Scholar 

Tisdall MD, Reuter M, Qureshi A, Buckner RL, Fischl B, van der Kouwe AJW. Prospective motion correction with volumetric navigators (vNavs) reduces the bias and variance in brain morphometry induced by subject motion. Neuroimage. 2016;127:11–22.

Article  PubMed  Google Scholar 

Izquierdo-Garcia D, Hansen AE, Forster S, Benoit D, Schachoff S, Furst S, et al. An SPM8-based approach for attenuation correction combining segmentation and nonrigid template formation: application to simultaneous PET/MR brain imaging. J Nucl Med. 2014;55:1825–30.

Article  PubMed  Google Scholar 

Ladefoged CN, Law I, Anazodo U, St Lawrence K, Izquierdo-Garcia D, Catana C, et al. A multi-centre evaluation of eleven clinically feasible brain PET/MRI attenuation correction techniques using a large cohort of patients. Neuroimage. 2017;147:346–59.

Article  PubMed  Google Scholar 

Tzourio-Mazoyer N, Landeau B, Papathanassiou D, Crivello F, Etard O, Delcroix N, et al. Automated anatomical labeling of activations in SPM using a macroscopic anatomical parcellation of the MNI MRI single-subject brain. Neuroimage. 2002;15:273–89.

Article  CAS  PubMed  Google Scholar 

Nutma E, Fancy N, Weinert M, Tsartsalis S, Marzin MC, Muirhead RCJ, et al. Translocator protein is a marker of activated microglia in rodent models but not human neurodegenerative diseases. Nat Commun. 2023;14:5247.

Article  CAS  PubMed  PubMed Central  Google Scholar 

Notter T, Coughlin JM, Sawa A, Meyer U. Reconceptualization of translocator protein as a biomarker of neuroinflammation in psychiatry. Mol Psychiatry. 2018;23:36–47.

Article  CAS  PubMed  Google Scholar 

Notter T, Schalbetter SM, Clifton NE, Mattei D, Richetto J, Thomas K, et al. Neuronal activity increases translocator protein (TSPO) levels. Mol Psychiatry. 2021;26:2025–37.

Article  CAS  PubMed  Google Scholar 

Liu GJ, Middleton RJ, Hatty CR, Kam WW, Chan R, Pham T, et al. The 18 kDa translocator protein, microglia and neuroinflammation. Brain Pathol. 2014;24:631–53.

Article  CAS  PubMed  PubMed Central  Google Scholar 

Bradburn S, Murgatroyd C, Ray N. Neuroinflammation in mild cognitive impairment and Alzheimer’s disease: a meta-analysis. Ageing Res Rev. 2019;50:1–8.

Article  CAS  PubMed  Google Scholar 

McDougle C, Landino S, Vahabzadeh A, O’Rourke J, Zürcher N, Finger B, et al. Toward an immune-mediated subtype of autism spectrum disorder. Brain Res. 2014;1617:72–92.

Carlezon WA, Kim W, Missig G, Finger BC, Landino SM, Alexander AJ, et al. Maternal and early postnatal immune activation produce sex-specific effects on autism-like behaviors and neu