Sonja E. Siennick

Sonja E. Siennick

Sonja Siennick studies criminal offending and mental health problems in the contexts of the life course and kinship and friendship relations. Her current project, funded by the National Institute of Justice, examines the prevalence and predictors of officially detected recidivism among juveniles. Other recent funded projects have examined the association of solitary confinement with mental health, substance use and peer problems among adolescents with depression, and the effectiveness of a school-based intervention for justice system–involved adolescents.

Research Interests

Crime and Deviance | Mental Health | Kinship and Friendship Relations | Life Course | Quantitative Methods


PhD. 2009, The Pennsylvania State University; Sociology

M.A. 2005, The Pennsylvania State University; Crime, Law, and Justice

B.A. 2001, Purchase College, State University of New York; Psychology


“A Mixed-Methods Examination of the Unique Root Causes of School Violence.” Co-Principal Investigator. National Institute of Justice, 2022-2024.

“A Two-State Examination of Varied Measurement Strategies for Reoffending.” Principal Investigator. National Institute of Justice, 2021-2023.

“The Impacts of Restrictive Housing on Inmate Behavior, Mental Health, and Recidivism, and Prison Systems and Personnel.” Research Advisor and Lead Analyst. National Institute of Justice, 2017-2019.

“The Palm Beach County School Safety and Student Performance Partnership Research Project.” Co-Principal Investigator of subcontract to Florida State University. National Institute of Justice, 2014-2018.

“Adolescent Friendship Networks and the Emergence of Substance Use.” Co-Investigator. National Institute on Drug Abuse, 2013-2018.

Recent Publications

Casey, William M., and Sonja E. Siennick. Forthcoming. Juvenile recidivism: An examination of state measurement strategies. American Journal of Criminal Justice.

Siennick, Sonja E., Jennifer M. Brown, Daniel P. Mears, and Jasmine A. Clayton. Forthcoming. A within-person test of the impact of extended solitary confinement on mental health functioning and service use. Criminal Justice and Behavior.

Siennick, Sonja E., Mayra Picon, Jennifer M. Brown, and Daniel P. Mears. 2022. Revisiting and unpacking the mental illness and solitary confinement relationship. Justice Quarterly 39(4): 772-801.

Siennick, Sonja E., and Jhon A. Pupo. Forthcoming. Exploring variation in the strength of association of a validated recidivism risk score with seven common measures of juvenile recidivism: A research note. Youth Violence and Juvenile Justice.

Siennick, Sonja E., and Alex O. Widdowson. 2022. Juvenile arrest and later economic attainment: Strength and mechanisms of the relationship. Journal of Quantitative Criminology 38: 23-50.

Widdowson, Alex O., Carter Hay, and Sonja E. Siennick. 2021. Romantic partners and young adult offending: Considering the role of partner’s socioeconomic characteristics. Criminology 59: 158-190.

Selected Publications

Siennick, Sonja E., Samantha J. Brown, Daniel P. Mears, George B. Pesta, Andrea N. Montes, and Nicole L. Collier. Forthcoming. School-based wraparound services for youth with prior police contact: A randomized controlled trial. Journal of Experimental Criminology.

Siennick, Sonja E., and Alex O. Widdowson. Forthcoming. Juvenile arrest and later economic attainment: Strength and mechanisms of the relationship. Journal of Quantitative Criminology.

Siennick, Sonja E., Alex O. Widdowson, and Mark E. Feinberg. 2020. Youth with co-occurring delinquency and depressive symptoms: Do they have better or worse delinquent outcomes? Journal of Youth and Adolescence 49(6): 1260-1276.

Siennick, Sonja E., and Mayra Picon. 2020. Adolescent internalizing symptoms and the “tightknittedness” of friendship groups. Journal of Research on Adolescence 30(S2): 391-402.

Widdowson, Alex O., Wade C. Jacobsen, Sonja E. Siennick, and Patricia Y. Warren. 2020. Together despite the odds: Explaining racial and ethnic heterogeneity in relationship dissolution following incarceration. Criminology 58(1): 129-155.

Widdowson, Alex W., J. Andrew Ranson, Sonja E. Siennick, D. Wayne Osgood, and Kelly Rulison. 2020. Exposure to persistent delinquent peers and substance use onset: A test of Moffitt’s social mimicry hypothesis. Crime and Delinquency 66(3): 420-445.

Cochran, Joshua C., Sonja E. Siennick, and Daniel P. Mears. 2018. Social exclusion and parental incarceration impacts on adolescents’ networks and school engagement. Journal of Marriage and Family80(2): 478-498.

Siennick, Sonja E., and Alex O. Widdowson. 2017. Incarceration and financial dependency during and after “youth.” Journal of Developmental and Life-Course Criminology 3(4): 397-418.

Siennick, Sonja E., Alex O. Widdowson, and Daniel T. Ragan. 2017. New students’ peer integration and exposure to deviant peers: Spurious effects of school moves? Journal of Early Adolescence 37(9): 1254-1279.

Siennick, Sonja E., Alex Widdowson, Mathew Woessner, Mark E. Feinberg, and Richard L. Spoth. 2017. Risk factors for substance misuse and adolescents’ symptoms of depression. Journal of Adolescent Health 60(1): 50-56.


405 College of Criminology and Criminal Justice BLDG (CRM) Mail Code: 1273
Office Hours

Monday: 1:00 PM - 4:00 PM 
Or by appointment

Resume / CV
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