Gabapentin can cause memory-related side effects in some people. In clinical trials submitted to the FDA, 2% of patients taking gabapentin for epilepsy experienced amnesia, compared to 0% on placebo. The risk appears to increase with longer use and may be more pronounced in certain age groups, though the overall picture from research is more nuanced than a simple yes or no.
What Clinical Trials Show
The FDA-approved prescribing information for gabapentin lists amnesia as an adverse reaction occurring in about 2% of epilepsy patients over age 12 in pooled clinical trials, versus 0% of those taking a placebo. Abnormal thinking, a broader category that includes difficulty with concentration and mental clarity, appeared in 2% to 3% of gabapentin users depending on the condition being treated, compared to 0% to 1% on placebo.
For children ages 3 to 12, the FDA label specifically warns about thought disorder, which includes concentration problems and declining school performance. These effects fall under a broader pattern of central nervous system side effects that also includes drowsiness and dizziness, both of which are common with gabapentin and can themselves make thinking feel foggy.
How Gabapentin Affects the Brain
Gabapentin works by binding to specific parts of voltage-gated calcium channels in the nervous system. These channels play a role in how nerve cells communicate, and the particular subunit gabapentin targets is also involved in forming new connections between neurons. Proteins released by support cells in the brain normally bind to this same site to promote the growth of excitatory synapses, the junctions where one nerve cell stimulates another. By occupying that binding site, gabapentin can interfere with this process.
This mechanism is what makes gabapentin effective for nerve pain and seizures: it dials down excessive nerve signaling. But the same dampening effect on neural communication could plausibly affect cognitive processes like memory formation, which depend on strong, well-functioning synaptic connections. The drug reduces overall excitatory activity in the brain, and memory encoding requires precisely that kind of activity.
Long-Term Use and Cognitive Decline
A large study examining patients who had received six or more gabapentin prescriptions found an increased incidence of both dementia (29% higher relative risk) and mild cognitive impairment (85% higher relative risk) compared to people not prescribed the drug. The risk climbed further with more prescriptions: patients with 12 or more had a 40% higher risk of dementia and 65% higher risk of mild cognitive impairment than those with only 3 to 11 prescriptions.
A separate study published in Alzheimer’s & Dementia looked specifically at older adults who started with normal cognition and tracked them over multiple follow-up visits. Gabapentin users were 57% more likely to show decline on a standard dementia rating scale at the first follow-up and 89% more likely to show decline on a more detailed version of that same scale. By the second follow-up visit, they were more than twice as likely to show decline in their ability to perform everyday tasks like managing finances or remembering appointments.
These findings don’t prove gabapentin directly caused the decline. People prescribed gabapentin often have chronic pain, sleep problems, or other conditions that independently affect cognition. But the pattern of increasing risk with longer use is consistent enough to warrant attention.
Age Makes a Difference
One of the more striking findings involves age. In the prescription frequency study, adults aged 18 to 64 who were prescribed gabapentin had over twice the risk of dementia and 2.5 times the risk of mild cognitive impairment compared to non-users. That relative risk was actually higher than what was seen in elderly patients, possibly because dementia is already more common in older populations, making the baseline comparison different.
Not all research agrees on the age question. A nested case-control study of chronic pain patients found no elevated dementia risk across different dosage levels regardless of age or gender. The authors concluded that long-term gabapentin use for chronic pain did not result in a significant difference in dementia risk between low and high dosages. This conflicting evidence suggests that individual factors, including why you’re taking gabapentin and what other health conditions you have, likely play a role in whether cognitive effects develop.
How Gabapentin Compares to Similar Drugs
Pregabalin, a closely related medication that works on the same receptor, has been studied more extensively for memory effects. A meta-analysis and systematic review covering both drugs found that short-term pregabalin use in healthy volunteers caused temporary central nervous system side effects but did not significantly impair memory on most assessments. Multiple studies using standard memory tests found no reduction in memory performance with pregabalin.
For gabapentin specifically, the clinical evidence on memory in non-epilepsy patients is thinner. One study found that a single preoperative dose of gabapentin reduced anxiety without impairing memory or causing sedation. However, this only tested short-term effects in a limited number of patients. The long-term picture, as outlined above, looks different. The review authors noted that extended use had not been adequately evaluated in controlled settings for gabapentin’s direct memory effects.
Recognizing Cognitive Side Effects
Memory problems from gabapentin don’t typically look like dramatic forgetting. More commonly, people describe a mental fog: difficulty concentrating, trouble recalling words, slower processing, or a sense that thinking requires more effort than usual. These symptoms often overlap with the drowsiness and dizziness that are among gabapentin’s most common side effects, affecting roughly 20% and 17% of users respectively in clinical trials.
These cognitive effects are most noticeable when you first start the medication or after a dose increase. For many people, they improve over the first few weeks as the body adjusts. If they persist or worsen, the dose or timing of the medication may need to be reconsidered. Stopping gabapentin abruptly after taking higher doses can also cause confusion and disorientation, so any changes should be gradual.
The practical takeaway: gabapentin does carry a real, measurable risk of affecting memory and cognitive function, particularly with long-term use. The effects range from mild fogginess that resolves with time to more persistent cognitive changes seen in longitudinal studies. If you’re noticing memory difficulties while taking gabapentin, that experience is consistent with what the clinical evidence shows.