However, it had nothing to do with drugs, she said.
Russell was found in California last Thursday in “various stages of undress”, “acting bizarrely, running into traffic” in public in California.
Mobile phone footage of the filmmaker bending over and slapping the concrete pavement before yelling out “iPhone Siri” and clapping quickly, spread across the web.
Russell’s documentary Kony 2012 chronicles the atrocities committed by Ugandan rebel leader Jospeh Kony and his Lord’s Resistance Army, including kidnapping children and forcing them to fight.
Russell’s wife Danica said in statement: “Jason’s incident was in no way the result of drugs or alcohol in his body.”
“The preliminary diagnosis he received is called brief reactive psychosis, an acute state brought on by extreme exhaustion, stress and dehydration.”
Russell was taken by police to a medical facility where he was treated for “exhaustion, dehydration and malnutrition”.
Danica’s announcement coincided with an anti-Kony resolution coming before the US Senate.
On Wednesday, a bipartisan group of 33 US senators introduced a resolution condemning Kony for crimes against humanity.
The senators pledged to support efforts to remove him from the battlefield.
It comes after a pledge by Barack Obama in 2011 to deploy 100 US combatants to central Africa to help government forces battle Kony.