Transcranial Magnetic Stimulation: A Cure for Depression

Transcranial magnetic stimulation utilizes a magnetic field to stimulate neurons in the brain. This can aid in rewiring the brain and altering neural pathways. In a TMS NeuroStar machine, a magnetic coil is used to stimulate the brain on the dorsolateral prefrontal cortex (dLPFC), a part of the brain that is involved in depression and mood changes. Short pulses of magnetic energy are sent to this region in order to "reset" the brain pathways and activate brain cells. It has been demonstrated that the activity of these brain cells are underactive in depression, but return to normal activity after treatment with a full course of Transcranial Magnetic Stimulation.

Depression affects millions of people worldwide and can be treatment-resistant in many people. The first-line treatments for depression are psychotherapy and antidepressants. While many different antidepressants exist, some people do not respond to medication or do not produce a response that alleviates enough symptoms. 

SSRIs

Depression is theorized to be caused by low levels of serotonin in the brain. Selective serotonin reuptake inhibitors work by sending signals to the brain to increase serotonin activity. SSRIs do not affect the other neurotransmitters, dopamine and norepinephrine. 

Prefrontal Cortex: Cognitive Control

While scientists are still not 100% certain how transcranial magnetic stimulation works, it is believed that the magnetic fields stimulates the brain to allow neurons to fire and create new pathways in the brain in the prefrontal cortex. The prefrontal cortex is utilized in the brain for judgement and decision making, and is often under-active in depressed patients. By stimulating the prefrontal cortex, the brain will then be able to make new connections and create more neural activity.

Cognitive control is a term used to describe these functions of the prefrontal cortex. Cognitive impairment is often seen in depression, and even after symptoms are in remission. Antidepressants typically only help with lack of motivation for activities and for mood symptoms, but do not necessarily help with the cognitive impairment that is often seen in depression. However, TMS has demonstrated improvement in cognitive control along with the other mood symptoms in depression, as it stimulates the prefrontal cortex that is in charge of cognitive control. 

Safety and Effectiveness

Transcranial magnetic stimulation is often considered more safe and effective than traditional treatments for depression. Electric convulsive therapy, ECT, has been previously used for patients that have severe depression that does not respond to first-line treatments. However, ECT can cause memory loss and other severe side effects. TMS does not have these drastic side effects, and the only side effects are usually mild scalp discomfort. This treatment is generally not recommended for people that are predisposed to having seizures, as this is a possible but rare side effect.