Routine Hair Testing Unmasks Hidden Synthetic Cannabinoid Use in Forensic Psychiatric Patients: A 10-Year Comparative...

Area of Science:

• Forensic Psychiatry
• Addiction Medicine
• Criminal Justice

Background:

• Germany's § 64 Criminal Code mandates two-year multimodal therapy for offenders with substance use disorders.
• The reintegration phase involves reduced supervision, where lapses, particularly synthetic cannabinoid (SC) use, are often concealed due to detection challenges.

Purpose of the Study:

• To compare the effectiveness of different monitoring strategies for synthetic cannabinoid (SC) use in forensic psychiatric patients.
• To evaluate the impact of standardized hair analysis versus case-dependent urine testing on SC detection rates.

Main Methods:

• A ten-year comparative study (2014-2024) of two forensic hospitals (Guenzburg and Kaufbeuren).
• Guenzburg implemented mandatory hair analysis and broad-spectrum SC screenings from 2019, while Kaufbeuren used case-dependent urine testing.
• 527 patients were included in the analysis.

Main Results:

• Guenzburg conducted significantly more tests and achieved a seven-fold higher SC detection rate using hair analysis compared to Kaufbeuren's urine testing.
• SC-positive patients were younger at first conviction, more often under substitution treatment, and had a higher likelihood of violent offenses.
• A history of violence quadrupled the odds of SC positivity.

Conclusions:

• Standardized long-term SC monitoring, particularly using hair analysis, is effective in forensic psychiatric settings.
• A history of violence is a significant predictor of SC relapse during the reintegration phase.
• Targeted monitoring strategies can improve detection and management of SC use in this population.