Total hypothalamic volume is reduced in postmortem brains of male heroin addicts.

The hypothalamus is at the core of the stress responses systems of the brain. Most interestingly, even though changes of HPA-function have been observed in opiate addiction not much is known about structural changes of the hypothalamus. Volumes of hypothalamus in heroin addicts (n = 14) and healthy controls (n = 12) were assessed by using morphometry of serial whole-brain sections. Total brain volume was larger in the heroin group (mean 1478.85 ± 62.34 cm3 vs. mean 1352.38 ± 103.24 cm3), as the heroin group was more than 10 years younger (p = 0.001). Thus, diagnosis-related effects in the hypothalamus were assessed using the hypothalamus volume relative to whole brain volume showing reduced volumes of the hypothalamus in the heroin group (0.201 ± 0.074 × 10-3 vs. 0.267 ± 0.048 × 10-3; ANOVA: F(1,23) = 6.211, p = 0.020) with a strong hemispheric effect (left side: about 20% reduction 0.209 ± 0.080 × 10-3 vs. 0.264 ± 0.049 × 10-3; F = 4.109; p = 0.054; right side: about 27% reduction, 0.198 ± 0.069 × 10-3 vs. 0.271 ± 0.050 × 10-3; F = -8.800; p = 0.007). Our results provide further evidence for structural and not only functional deficits of the hypothalamus in addiction.