Increased β-endorphin level in blood plasma as an indicator of positive response to depression treatment.

Preliminary data indicate that increased blood plasma level of β-endorphin in patients with nonpsychotic unipolar depression after 2 weeks of treatment correlates with the positive response to therapy. This parameter can be regarded as an objective indicator of potential improvements. Further studies aimed at determining the value of blood β-endorphin levels in patients with mood disorders for the diagnostics and estimating the therapeutic success in this disease are required.