Hair zinc levels a potential biomarker for assessing psychosis risk in teens

Lower levels of zinc in hair may be a warning signal for psychosis among treatment-naïve adolescents, a study has found.

The study used data from a population-based biomarker subsample study of the Tokyo Teen Cohort Study to determine whether zinc and copper levels in hair were associated with psychosis risk among drug-naïve adolescents.

A total of 252 community-dwelling drug-naïve adolescents (mean age 178.9 months, 53.17 percent male) were included in the analysis. Inductively coupled plasma mass spectrometry was used to measure zinc and copper levels in hair, while the thought problems (TP) scale from the Child Behavior Checklist was used to assess psychosis risk.

At baseline, mean TP scale (T-score) was 58.7, mean hair zinc levels were 150.0 ppm, and mean hair copper levels were 21.7 ppm. There were no sex-related differences seen in the parameters except for hair copper levels, which were significantly elevated in girls than in boys (p=0.002).

With a T-score of the TP scale >68.5 considered as the cutoff for psychosis, 80 participants (31.7 percent) met the criteria for possible psychosis. The hair zinc levels of this group of participants were significantly lower than those of the other 172 participants (p<0.01).

Regression analysis revealed a negative correlation between hair zinc levels and the TP scale T-score (β, −0.176, p=0.005). This association persisted despite adjustments for age and sex (β, −0.175, p=0.005).

On the other hand, there was no association noted between hair copper levels and the TP scale T-score (β, 0.026, p=0.687).

The present data indicate the possibility of lower zinc levels being involved in the pathophysiology of psychosis, independent of antipsychotics. Additional longitudinal studies are required to investigate the utility of hair zinc level as a new biomarker for assessing psychosis risk.