Three of those injured in the attack were taken to hospital in a serious condition, including a 12-year-old girl who remains in a critical condition.
The suspect had been known to police prior to the attack but not to France's intelligence services, local media report.
He alleged that it was being used to portray the suspect as criminally irresponsible rather than having acted deliberately.
PNAT added that the suspect was also found to have cannabis and cocaine in his bloodstream.
Authorities said he will be observed to evaluate whether his psychiatric health is compatible with pursuing his interrogation. PNAT said the move to place the suspect under psychiatric evaluation followed guidance from a psychiatric expert.
PNAT said the move to place the suspect under psychiatric evaluation followed guidance from a psychiatric expert.
PNAT said the suspect was also found to have cannabis and cocaine in his bloodstream.