APA Dictionary of Psychology

a neurosurgical procedure used most commonly to treat the disabling neurological symptoms of Parkinson’s disease (e.g., tremor, rigidity, stiffness, dyskinesia), particularly when such symptoms cannot be adequately controlled with medications. An electrode is inserted through a small opening in the patient’s skull and implanted in the brain, and an insulated wire passed under the skin of the head, neck, and shoulder connects the electrode to a neurostimulator, which (similar to a heart pacemaker) is usually implanted under the skin near the collarbone. Electrical signals from the neurostimulator trigger the electrode to begin emitting small impulses of electricity to areas in the brain that control movement, blocking abnormal nerve signals that cause tremor and other neurological symptoms. DBS is also used for people with highly treatment-resistant major depression if multiple medications, psychotherapy, and electroconvulsive therapy have failed. The procedure does not damage healthy brain tissue by destroying nerve cells, and it is reversible. Potential side effects of DBS include a slight decline in memory and executive functioning.