Mind-bending psychedelic drugs such as LSD can re-wire the brain and mend broken connections between neurons, new research suggests.
The discovery could lead to new treatments for anxiety, addiction and post-traumatic stress disorder, scientists believe.
In tests on flies and rats, the US team found that a wide range of psychedelic drugs promote “neural plasticity” and alter brain structure.
Exposure to the hallucinogenic drugs led to the growth of dendrites, dendritic spines and synapses, all of which help neurons communicate with one another.
Dendrites are branch-like bodies that extend from nerve cells, which in turn sprout tiny dendritic “spines”.
Synapses are the all-important connection points that allow chemical signals to flow between neurons.
The changes seen in the animals’ brains are almost certain to occur in humans too, say the researchers, whose findings appear in the journal Cell Reports.
Previous experiments have shown that psychedelic drugs induce similar effects across species.
Lead scientist Dr David Olson, from the University of California at Davis, said: “People have long assumed that psychedelics are capable of altering neuronal structure, but this is the first study that clearly and unambiguously supports that hypothesis.”
One of the hallmarks of depression is that nerve fibres and dendrites “tend to shrivel up”, he said.
Similar changes were seen in cases of anxiety, addiction and post-traumatic stress disorder (PTSD).
Katamine, an anaesthetic also used as a recreational “club drug”, was already known to alter brain wiring.
In previous studies, it has been shown to produce rapid anti-depressant effects. However, there are serious side effects associated with ketamine, including high blood pressure, impaired memory and delerium.
Dr Olson added: “If we fully understand the signalling pathways that lead to neural plasticity, we might be able to target critical nodes along those pathways with drugs that are safer than ketamine or psychedelics.”
The scientists carried out experiments using LSD, DMT – a psychedelic drug derived from ayahuasca, an Amazonian herbal tea – and DOI, an hallucinogenic form of amphetamine.
In one study, DMT enabled rats to overcome fearful memories of suffering an electric shock. The test mimicked PTSD in humans.
