Association Between Hair Lithium Levels and Suicide: A Case-Control Study

Area of Science:

• Forensic Science
• Toxicology
• Psychiatry

Background:

• Hair analysis offers a stable method for long-term trace element monitoring, reflecting chronic exposure.
• Previous research suggests links between low hair lithium (Li) levels and mental illness or violent behavior.
• The relationship between hair Li levels and suicide has not been previously investigated.

Purpose of the Study:

• To investigate the association between hair lithium concentrations and suicide.
• To determine if hair Li levels can serve as a biomarker for suicide risk.

Main Methods:

• A case-control study was conducted on deceased individuals.
• Hair samples from 25 suicide cases and 27 non-suicide controls were analyzed.
• Lithium concentration was measured using Inductively Coupled Plasma-Mass Spectrometry.

Main Results:

• No significant differences in hair Li content were observed between the suicide and control groups.
• Hair Li concentrations ranged from <3 to 42 µg/kg, with low variability.
• Mental disorder was significantly associated with suicide (OR, 22.74; p=0.009) after adjustment for other factors.

Conclusions:

• Hair lithium concentrations do not differ between suicide victims and controls in this population.
• No association was found between hair Li levels and suicide in this study.
• Mental disorder is a significant risk factor for suicide.