Ketamine is a medication that was originally developed as an anesthetic, but in recent years, it’s been found to have powerful effects in treating depression, anxiety, and other mood disorders — especially when traditional treatments haven’t helped.

What makes ketamine unique is how quickly it works, and how it works — not just by changing brain chemistry, but also by changing brain structure and function in ways that support healing.

Unlike most antidepressants, which target serotonin or other neurotransmitters, ketamine primarily works on the glutamate system — the brain’s main excitatory neurotransmitter. When ketamine is administered at low doses, it stimulates a burst of glutamate activity, which triggers a cascade of changes in the brain.

One of the most important effects of this is that ketamine helps promote neuroplasticity — the brain’s ability to form new connections. It increases the growth of synapses (the connections between brain cells), particularly in areas of the brain that are often weakened in people with depression — like the prefrontal cortex, which helps with emotional regulation, perspective-taking, and decision-making. This means ketamine helps the brain ‘rewire’ itself, often allowing for new patterns of thought and feeling to emerge.

Ketamine also affects something called the default mode network (DMN) — a part of the brain that’s active when we’re thinking about ourselves, ruminating, or replaying memories. In people with depression and anxiety, the DMN tends to be overactive, leading to excessive self-criticism, looping negative thoughts, and difficulty being present. Ketamine temporarily quiets the DMN, which may explain why people often report a sense of space, openness, or even relief from the constant mental chatter during and after treatment.

This ‘reset’ effect on the DMN can allow individuals to step outside of their usual thought patterns and access new insights or perspectives — and that’s where therapy becomes especially powerful. When used in combination with talk therapy or integration work, ketamine can help you process past experiences, reframe old beliefs, and reconnect with a deeper sense of self.

In short, ketamine isn’t just numbing symptoms — it’s helping the brain create new conditions for healing. It supports the structure of the brain (by promoting neural growth) and the function of the mind (by loosening rigid patterns and opening space for change).