Thalamic stimulation effects on reactive depression.

Depression was evaluated in 10 patients before and after therapeutic mesothalamic brain stimulation for chronic pain. Minnesota multiphasic personality inventory T scores for depression were high in all patients before stimulation. Scores were decreased in 8 of 10 patients with chronic deep brain stimulation, three of whom returned to normal. Pain relief was good to excellent in 9 of 10 patients. It is concluded that depression is secondary to pain or pain-inducing factors which implicate the catecholamine and serotonergic systems.