Gabapentin
Gabapentin (Neurontin) is a “gabapentinoid” often used for nerve pain and seizure disorders, and sometimes off-label for anxiety/sleep. Even though it was designed as a GABA analog, it doesn’t act like GABA directly—its main mechanism is binding the α2δ subunit of voltage-gated calcium channels, which reduces release of excitatory neurotransmitters and can calm overactive nerve signaling (1). Common side effects are drowsiness/somnolence, dizziness, brain fog/coordination issues, and sometimes edema; it can also compound sedation when combined with other CNS depressants, and the FDA has warned about respiratory depression risk in higher-risk situations (especially with opioids or underlying lung issues) (2).
In the PFS/PSSD/PAS context, gabapentin isn’t widely described as a classic “PSSD-causer,” and you don’t see as many direct “permanent crash” stories compared with strongly serotonergic drugs—but it still meaningfully alters neuro-signaling, so flares can happen in sensitive individuals. For many, if it helps at all, it’s more of a symptom band-aid(sleep, anxiety, pain, wired-but-tired feeling) rather than a true treatment of the underlying condition. The cautious framing for your site: lower-to-moderate crash risk, but still something to approach carefully (start low, one change at a time, watch for sedation/cognition effects, and avoid risky combinations).
(1) https://pmc.ncbi.nlm.nih.gov/articles/PMC4804325/
(2) https://www.accessdata.fda.gov/drugsatfda_docs/label/2017/020235s064_020882s047_021129s046lbl.pdf
Anecdotes:
https://www.reddit.com/r/PSSD/comments/1pn6554/i_found_in_reddit_sub_like_gabapentin_and/
My Personal Risk Ranking:
Low Risk of Permanent Worsening (for PFS/PSSD/PAS):
If you currently have PFS/PSSD/PAS, gabapentin is generally considered a lower-risk option for permanent worsening, but it can still trigger flares in some people because it significantly alters nervous-system signaling (via the α2δ calcium-channel pathway). Most community experiences describe it as more of a symptom band-aid (sleep, anxiety, nerve pain) than a true treatment of the underlying condition. For most people, it’s reasonable to approach it with caution—start low, change one thing at a time, avoid mixing with other sedatives, and stop if you notice a clear, consistent worsening.