Does TMS Cause Memory Loss?

If you're considering transcranial magnetic stimulation (TMS), it's completely understandable to wonder whether stimulating the brain could affect your memory. The reassuring news is that research shows TMS does not cause memory loss. Much of the concern comes from confusion with electroconvulsive therapy (ECT), another depression treatment that can cause memory-related side effects.

Quick answers

• There’s no research to show that TMS causes memory loss. 
• TMS works differently than ECT, and is not associated with the short-term memory loss sometimes seen with ECT.
• As depression symptoms improve, many people find that their memory, focus, and concentration improve, too.

What the research shows about TMS and memory

A review published in Experimental Neurobiology found that cognitive testing did not show meaningful declines in memory or thinking skills after TMS therapy — and in some cases, these metrics actually improved.

Part of the confusion comes from the fact that TMS is sometimes grouped together with ECT, another treatment for depression. But the two treatments work differently. 

"We’re not stimulating the brain quite in the same way that ECT is," says Jessica Criser, PMHNP-BC, a psychiatric nurse practitioner at Radial. "We're not inducing a seizure in the brain, which is why some short-term memory loss can occur [with ECT]."

In fact, many people notice the opposite effect. Depression itself can make it harder to concentrate, stay focused, and remember things. As those symptoms begin to improve, memory and cognition often get better, too. Criser says that’s why clearer thinking and improved cognition are often among the earlier signs that treatment is starting to work.

Why some people feel foggy during TMS

Some people describe feeling foggy, mentally drained, or like they're having trouble finding the right words during treatment. While these TMS side effects can be unsettling, they're not the same thing as memory loss.

Part of the reason is that TMS stimulates the prefrontal cortex, an area of the brain involved in thinking, focus, and executive function, according to Michael Denoyer, MHS, PA-C, a physician assistant at Radial. In other words, the treatment targets some of the same brain networks involved in mental clarity.

And as those networks become more active, the brain may need time to adjust. Criser compares the process to returning to the gym after a long break. Just as muscles can feel sore and tired as they get used to exercising again, the brain can feel temporarily fatigued as neural connections become more active.

"TMS is like giving your brain a high-intensity workout," says Denoyer. "You can feel a little fatigued afterward."

Both experts say that these feelings are typically temporary and tend to improve as treatment continues. Still, if the fogginess feels severe, persists, or simply doesn't feel right to you, it's worth bringing up with your provider.

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