Richard, now 37, had lived with the brain injury for 17 years when his family agreed to try the sleeping pill treatment.
Doctors have found sleeping pills can help some patients with brain injuries temporarily regain speech and movement.
According to Cortex, Richard regained full consciousness, recognised his family and asked to speak with his dad after he was given a dose of Zolpidem.
The family had agreed to the Zolpidem, otherwise known as Ambien, treatment after doctors admitted there was little left for them to do.
Student doctor Willemijn van Erp, from Radboud University in the Netherlands, was involved in Richard's treatment at a specialised nursing home.
"It was clear that Richard saw and heard us, but because of his brain injury, he was barely able to respond to us," she told Cortex.
Within 20 minutes of the sleeping drug being administered, Richard was asking the nurse how to operate his wheelchair, asked for his dad and said he was craving fast food.
"Because Richard's situation seemed hopeless, the family and I decided to administer this medication to Richard," Van Erp said.
"Against all expectations, Zolpidem had remarkable effects.
"After taking the sleep pill, Richard started talking, wanted to call his father, and started recognising his brothers again.
"With some help, he could even get up from his wheelchair and walk short distances."
Medical investigation into sleeping pills and their effect on the brain have found the sedative part of the drug can help to mute unnecessary brain activity.
Doctors found part of Richard's brain had completely shut down because they were being overloaded with sensory activity.
Taking the sleeping pill was able to stop that explosion of activity for around two hours, allowing Richard to converse with people and walk again.
Dr Hisse Arnts at Amsterdam UMC said doctors replicated the treatment for a number of days before the drug stopped having an effect.
"Richard's brain scans show overactivity in certain parts of the brain," Arnts said.
"This overactivity causes noise and somehow shuts down the 'good' brain activity.
"We have discovered that administering this sleeping medication can suppress this unwanted brain overactivity, creating space for speech and movement."
Doctors repeated the treatment once a day for five days before the effects started to wear off.
"The time windows during which the patient was able to talk and move got narrower, and his abilities to move and speak during these time windows decreased," Arnts told Cortex.
"The use of multiple doses of zolpidem during a single day showed no improvement in his clinical condition and sometimes even caused sedation."
An earlier study with sleeping pills and patients with brain injury showed the treatment had a 5 per cent success rate.
Akinetic mutism is a condition different to comas or paralysis, as some patients are able to make sounds or open their eyes.
Researchers continue to look into a permanent treatment for patients with brain injuries.