Jason Russell, 33, was hospitalized last week in San Diego after witnesses saw him running through streets in his underwear, screaming incoherently and banging his fists on the pavement.
His outburst came after the video's sudden success on the Internet brought heightened scrutiny to Invisible Children, the group he co-founded in 2005 to fight African war atrocities.
Russell's family reiterated that the filmmaker's bizarre behavior was not due to drugs or alcohol. He was given a preliminary diagnosis of brief reactive psychosis, in which a person displays sudden psychotic behavior.
"Doctors say this is a common experience given the great mental, emotional and physical shock his body has gone through in these last two weeks. Even for us, it's hard to understand the sudden transition from relative anonymity to worldwide attention -- both raves and ridicules, in a matter of days," Danica Russell said in a statement.
Researchers don't know how many people suffer from the condition, mainly because symptoms are fleeting, but those with personality disorders are at greater risk for having an episode. Brief reactive psychosis is triggered by trauma or major stress such as an accident or death of a loved one. Other stressors can include sleep deprivation or dehydration.
Symptoms include hallucinations, delusions and strange speech and behavior. People typically recover within a few weeks without medication. Others have to take antipsychotic drugs to alleviate symptoms or undergo talk therapy to cope.
The condition causes "temporary debilitation, but in general people have good recoveries," said Dr. Stephen Marder, professor of psychiatry at the University of California, Los Angeles.
In some cases, doctors say brief reactive psychosis can signal the beginning of a more serious mental illness such as schizophrenia.
Danica Russell said it may be months before her husband returns to San Diego-based Invisible Children.
"Jason will get better. He has a long way to go, but we are confident that he will make a full recovery," she said.
Russell narrates the 30-minute video "Kony 2012," which has been viewed more than 84 million times on YouTube since it was released this month. In the video, Russell talks to his young son, Gavin, about Kony and the Lord's Resistance Army.
The Invisible Children group has been criticized for not spending enough directly on the people it intends to help and for oversimplifying the 26-year-old conflict involving the LRA and its leader, Kony, a bush fighter wanted by the International Criminal Court for crimes against humanity.
Invisible Children has acknowledged the video overlooked many nuances but said it was a "first entry point" that puts the conflict "in an easily understandable format." It said money that directly benefits the cause accounted for more than 80 percent of its spending from 2007 to 2011.