Russell was seized by cops in San Diego, California last Thursday (15Mar12) for public drunkenness and masturbation following reports he was seen committing an obscene act and vandalising cars.
He was placed on a psychiatric hold so medics could assess his mental state, and now a spokesman for the family has revealed Russell was diagnosed with a brief reactive psychosis - a temporary psychotic episode triggered by stress.
He is likely to remain in hospital for several weeks.
The statement, obtained by TMZ.com, reads, ""We would, again, like to make it clear that 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...
""Though new to us, the 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...
""He is, and will remain, under hospital care for a number of weeks; and after that, the recovery process could take months before he is fully able to step back into his role with Invisible Children. During that time, we will focus not on a speedy recovery, but a thorough one.""
Russell's film about Joseph Kony became an online hit when it was released earlier this month (Mar12) to bolster Invisible Children's upcoming 20 April (12) publicity drive to snare the warlord, but became mired in controversy amid allegations of financial mismanagement at the charity and reports Kony has not been active in Uganda for years.