TOPLINE:

Methamphetamine use disorder (MUD) was associated with significantly lower levels of serum melatonin and disrupted circadian patterns compared with not having MUD, a new study showed. Melatonin levels also showed strong negative correlations with substance craving scores, indicating that melatonin may serve as a biomarker of circadian irregularities linked to addiction.

METHODOLOGY:

• The study included 30 men with MUD (mean age, 26 years) receiving inpatient treatment and 20 healthy men acting as the control group (mean age, 25 years).
• Participants completed the Insomnia Severity Index (ISI) and the Substance Craving Scale (SCS), with higher scores indicating greater severity.
• Blood samples were collected at 23:00, 02:00, and 06:00 after 8-12 hours of fasting, and serum melatonin levels were measured using enzyme-linked immunosorbent assay.
• Potential associations between melatonin levels and clinical variables, including age, duration of substance use, BMI, and ISI and SCS scores, were analyzed in multivariate analyses.

TAKEAWAY:

• Melatonin levels at all three timepoints were significantly lower in patients in the MUD group than those in the control group (P < .001 for all).
• In patients with MUD, melatonin levels showed an altered pattern, continuing to rise until peaking at 06:00 — unlike the normal circadian rhythm observed in control individuals, where melatonin levels peaked at 02:00 and declined by 06:00.
• Melatonin levels showed a significantly negative correlation with SCS scores at all timepoints (P < .001 at 23:00; P = .002 at 02:00; P = .014 at 06:00) and with ISC scores at 23:00 (P = .006) and at 2:00 (P = .048).
• In multivariate analyses, only the SCS score was identified as a significant independent predictor of melatonin levels at 23:00 (P = .006) and 02:00 (P = .01).

IN PRACTICE:

“These findings support the potential regulatory role of melatonin not only on circadian rhythm but also on substance craving. Melatonin can be considered as an important biomarker on addictive behaviors,” the investigators wrote.

However, researchers added that because this is thought to be the first study to measure melatonin within MUD, “replication is warranted.” 

SOURCE:

This study was led by Seda Yilmaz, MD, Elaziğ Fethi Sekin City Hospital, Elaziğ, Turkey. It was published online on October 28 in the Journal of Psychiatric Research.

LIMITATIONS:

The limited sample size of this study restricted the generalizability of the findings. Additionally, as only men were included, the results were not applicable to women.

DISCLOSURES:

The investigators reported no relevant conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.