Baseline characteristics.

<p>Mann Whitney U tests were performed; all data are expressed as means±SD.</p

Body composition and resting energy expenditure (measured by BIA and indirect calorimetry, respectively).

<p>Mann Whitney U tests were performed; all data are expressed as means±SD; *indicates statistical significance.</p

Salivary cortisol, urinary catecholamines and dopamine, and plasma metanephrines and 12-hour excretion rates of urinary metanephrines.

<p>Mann Whitney U tests were performed; all data are expressed as means±SD; *indicates statistical significance.</p

Parameters of sleep continuity and sleep architecture (polysomnographic study).

<p>Mann Whitney U tests were performed; all data are expressed as means±SD; *indicates statistical significance.</p

Midnight and morning salivary cortisol concentrations in insomniacs and controls.

<p>Midnight values were significantly higher in insomniacs than in controls (p = 0.02), whereas morning values did not differ significantly (p = 0.18).</p

Recruitment of participants.

<p>Recruitment of participants.</p

Effects of heroin on brain perfusion in contrast to placebo.

<p>BA: Brodmann area; L: left; P: perfusion; R: right; WM: white matter;</p>*<p>: p≤0.05;</p>***<p>: p≤0.001.</p><p>Each coordinate triple is a peak area of contrast intensity in one of the two significant clusters and refers to a specific area defined in the atlas of Talairach & Tournoux (1988).</p

Regional perfusion values of significant clusters.

<p>ACC: Anterior cingulate cortex; CI: Confidence interval; MPFC: Medial prefrontal cortex.</p