Approximately ten to thirty percent of patients with depression do not respond to drug treatments commonly used for the disorder, and this has spurred a search for alternatives. According to Kalorama Information's report "Electrical and Magnetic Neurostimulation," electrode devices that stimulate nerves have emerged as a solution and there is competition among notable device companies to provide the most effective stimulator.
Between 15 and 20 million people in the U.S. alone suffer from depression and Kalorama estimates the patient population corresponds to a potential market value of $16 billion annually for all cases of depression and a $4-5 billion potential market for drug refractory cases. This potential has attracted the notice of pharmaceutical, medical device and microelectronics companies. Although the device route is limited by its cost, which at the current time exceeds that of drug therapy, the cost differential could be reimbursed through savings in antidepressant drug costs.
"Depression treatment has made strides with modern pharmaceuticals, but there is a significant patient population that is refractory to treatment," said Mary Ann Crandall, Kalorama Information's analyst. "This should encourage regulatory agencies and insurance companies to become more receptive to newer approaches, which would further increase demand for these devices."
There are several device approaches to a potential stimulation treatment for depression. Vagus nerve stimulation uses an implanted stimulator that sends electric impulses to a nerve in the patient's neck via a lead wire implanted under the skin. VNS implantation devices consist of a titanium-encased generator about the size of a pocket watch, a wire system with electrodes, and an anchor tether to secure leads to the vagus nerve. Currently Cyberonic VNS Therapy ® is the only vagus nerve stimulator on the market, though there are companies developing external devices that do not require surgery. Repetitive TMS (rTMS) uses electrical pulses repeatedly passed through a coil placed on the scalp. The pulsating magnetic field generated by the coil penetrates the skull and disturbs the underlying neuronal equilibrium. Neuronetics is the leading provider of TMS systems with its NeuroStar TMS therapy system. Both technologies have FDA approval for major depression cases. The devices are safe and do not produce seizure.
In its report, Kalorama notes that important companies in the device industry are looking to enter this market. Medtronic and St. Jude's Medical produce deep brain stimulation (DBS) systems currently used to treat Parkinson's and dystonia and both companies are investigating adaptation to depression treatment. Boston Scientific produces a spinal cord stimulation system and is also reportedly developing depression treatments. Continued research, testing, and approval cycles must be completed before new devices move to market, but based on current developments, Kalorama sees a viable depression device treatment market in a five year timeframe.
Kalorama Information's market research report "Electrical and Magnetic Neurostimulation" covers all aspects of nerve stimulation, including pacemakers, spinal cord stimulation, TENS and other treatments. Markets are estimated and forecasted for the next five years and major companies are profiled.
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