Vladimir Putin's decision to avoid almost all contact since the start of the pandemic has brought on "signs of psychosis and a personality disorder" a leading psychotherapist believes.
The reclusive Russian dictator has been self-isolating since March 2020, only making occasional appearances.
It may have caused "irreversible" damage, the expert says, and the move to cut-off could be a factor in his decision to invade Ukraine, he told Express.co.uk.
Putin is currently living in a massive underground city protected from potential attacks, it has been claimed.
The President has retreated to a vast nuclear bunker as he lives in fear of his enemies.
He is exhibiting behaviours of psychosis and psychotherapist Noel McDermott says it appears Putin is displaying symptoms of paranoia, according to Express.co.uk..
He said: "At the beginning of the lockdown, Putin isolated himself and stayed isolated from people even until this point. Even now, he is still physically isolating.
"His behaviour is totally antisocial and indicates somebody who either has a personality disorder, which is a possibility, or it shows he is extremely afraid and paranoid."
He added: "One of the ways you punish somebody in prison is by putting them in isolation and people don't understand how damaging isolation is.
"It will cause irreversible psychological damage.
"The voices inside Putin's head would likely have become so much more real."
Tatiana Stanovaya, of the political analysis firm R.Politik, previously said: “He has withdrawn into himself a lot during the past two years. He has become distanced from the bureaucratic machinery, from the establishment, from the elite.
"He spends a lot of time alone stewing in his own fears and thoughts."
Putin has avoided meetings in person - or across ludicrously long tables, using a body double and ensuring his security team test his food before he eats.
It comes after Professor Valery Solovey stated the Russian President and the country's Defence Minister have retreated into an enormous nuclear bunker east of the Urals that can "house 100,000 people".
He also reiterated his forecast that Putin would be forced to quit politics at some point this year.
Solovey - who claims to have high-level Kremlin insider sources - has long alleged Putin suffers from cancer and other medical conditions, a theory for which he has provided no hard evidence.
“I didn’t say he’ll finish his earthly existence, these are different things,” he said.
“I said he won’t be in politics in [by the end of] 2022, and as far as I know nothing changed in this regard.”