Did Harry Potter have a severe mental illness?

My sons agree with Nicole Borland who writes,

The entire Harry Potter series is an extended metaphor about a boy with severe mental illness, suffering from delusions. Everything depicted in the movie can be interpreted as an attempt to cope with the harsh realities of his confinement in a mental institution. Every major event in the books is a fantasy/delusional version of the experiences that a child would encounter in the course of being institutionalized and forcibly treated for mental illness.

...The Harry Potter series, then, was written about the kind of experiences that institutionalized children encounter, the kind that J.K. Rowling (actively through her charities) is working to eradicate, but most people simply see it as an adventure story about magic. It's not about magic. It's about mental trauma and the delusion that results from it.

The final reinforcement of this idea comes towards the very end, when Harry appears in his imagined version of King's Cross with Dumbledore.

"Tell me one last thing," said Harry. "Is this real? Or has this been happening inside my head?"

"Of course it is happening inside your head, Harry, but why on earth should that mean that it is not real?"

Read more here.

Thanks to Jon Agard