Could gene-editing be used to treat mental illness?
Just as the technology is promising new therapies for everything from heart disease to cancer, some researchers believe that tinkering with the epigenome could help reverse the damage done by trauma.
In recent years, scientists have made strides towards treating diseases through gene-editing technology, their most promising breakthrough being the discovery of CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats).
The essence of CRISPR is simple: it’s a way of finding a specific bit of DNA inside a cell.
After that, the next step is to store the genetic code of a virus once it’s encountered so that the next time it tries to attack, the bacteria recognise the virus and remain unaffected.
Though still in its early stages, CRISPR gene-editing has already proved effective in clinical trials for the treatment of cancer, blood disorders, and cystic fibrosis.
In the quest to optimise human health, it’s even been considered as a means of preventing diseases from emerging in the first place with an ethically questionable ‘designer baby’ process that involves giving embryos natural immunity from the start of their growth.
But did you know that gene-editing technology might also hold the key to treating mental illnesses like addiction, depression, and anxiety?
As implied by growing evidence, childhood trauma biologically embeds itself in our bodies, alters how our genes work, and puts our mental health at risk.
If this thinking holds up, some researchers believe that tinkering with the epigenome could help reverse to this damage — or in their words, ‘physically edit out the scars of the past.’
‘Early life trauma is the strongest risk factor for a range of psychiatric conditions, most particularly depression and anxiety,’ says psychiatrist and neuroscientist Eric Nestler, citing a 2010 paper that found almost all kinds of childhood trauma to be associated with mental illness in adulthood.
Interestingly, the analysis suggested that if we somehow got rid of all childhood adversity, we would see a reduction in mental health diagnoses by almost one third.
This is where CRISPR comes in, more specifically Crispr-Cas9, where the Cas9 enzyme is deactivated so it can’t snip the DNA.
‘It’s not like cutting the gene and inserting something,’ says Subhash Pandey, a neuroscientist at the University of Illinois Chicago.
‘Instead, it simply finds the right point in the genome and can then remove or add a tag.’
In a study last May, Pandey used this epigenetic version called Crispr-dCas9 to undo an epigenetic change induced by teenage binge drinking in rats.
Rats that had been injected with alcohol in adolescence were significantly more anxious than teetotal fellow rodents, but when Pandey reversed the alcohol-induced change, their anxiety dropped to normal levels.
Of course, there’s a long way to go before epigenetic reprogramming could be used in humans, though Nestler thinks it holds significant potential in mitigating the effects of early exposure to trauma and subsequent mental illness.
‘Most efforts in the field over decades have been to undo the bad effects of stress,’ he says.
‘One could also try to institute mechanisms of natural resilience. Epigenomic editing has high potential for future therapy.’