It may sound unlikely, but party-drug and anaesthetic ketamine proves to do a good job as antidepressant. Studies show that about 70% of patients that don’t respond to conventional antidepressants do benefit from ketamine. The effects usually last for a couple of days. If the treatment is repeated several times, this can build up to weeks or months.
In contrast to regular antidepressants, 'Special K' even has a remarkably rapid onset. Within an hour patients suffering from long-term depressive episodes experience a relief of their symptoms. Regular antidepressants usually need a couple of weeks to take effect.
The synthetic was developed in the 60s and gained reputation as ‘horse anaesthetic’. Soon after its development people started to experiment recreationally with it for its psychoactive effects. In low doses ‘keta’ gives a mild, dreamy feeling, reminiscent of nitrous oxide. In a higher dose ketamine is hallucinogenic and dissociative: users often feel disconnected to their body (or parts of it), which can result in an out-of-body experience: the notorious K-hole.
Ketamine is listed as a regular anaesthetic for both humans and animals. Since 10 years its potential as antidepressant is investigated - up till now only in patients that don’t respond to conventional depression treatments. Results are promising, but safety and long-term effects need to be investigated further before it can be registered as official antidepressant. Nevertheless, some therapists already started to administer it off-label to depressive patients.
Contrary to other antidepressants, ketamine doesn’t affect the serotonergic system, but works on a different neurotransmitter, glutamate, by blocking N-methyl-D-aspartate (NMDA) receptors. The exact mechanism is quite complex and not fully understood yet, but brain scans show it activates the prefrontal lobe, which is usually less active in depressive patients.
Ketamine stimulates the growth of new synaptic connections between neurons. According to Dutch researcher Ruud Kortekaas depressive persons usually don’t show much variation in their thoughts. Ketamine helps to develop new thought patterns by which patients get a new outlook on reality.
For antidepressant purposes ketamine is usually administered intravenously in low doses. Treatment is quite expensive, as it requires continuous monitoring and needs to be repeated several times to have the best effects. As the medication isn’t approved of yet, it’s not covered by health insurances. Experiments with easier methods of administration, for example as a nasal spray or pill, are currently taking place.
Most patients describe the dissociative, ‘trippy’ side-effects of ketamine as pleasant. As doses are relatively low these side-effects are mild and don’t last much longer than the actual treatment. Currently, pharmaceutical companies are also developing ketamine-similar substances that don’t have the psychoactive effects.
Self-medication with ketamine is discouraged, mainly because the dissociative effects can lead to dangerous situations. As ketamine increases both heart rate and blood pressure, continuous monitoring during administration is required. Furthermore illegally obtained ketamine could be impure and contain dangerous mix products.
Read more about ketamine in our encyclopedia.
Written by: Juniper