March 5, 2007 -- The scene was a shocking one: Children, 2 and 4, inhaled deeply on a marijuana cigarette with encouragement from their 18-year-old uncle.
The incident, recorded on videotape by another juvenile, aired widely on cable news stations and eventually led to the two Fort Worth, Texas, toddlers being sent to foster care.
According to Marissa Gonzales, a spokeswoman for Tarrant County Child Protective Services, doctors examining the children after the incident said any marijuana they may have ingested would not have any long-term effects.
However, child psychology and addiction experts said that the episode could have troubling implications for the future psychology and health of these young victims.
"The consequences are very serious and a great concern," said David Farb, chairman of Boston University's Department of Pharmacology and Experimental Therapeutics.
"It's hard to imagine there not being some kind of change," he said. "My opinion is that the risk of addiction would be higher."
A Toxic Environment
Most troubling, child psychology experts said, is the fact that such an episode was allowed to occur in the first place.
"The biggest danger to these kids is the lack of parental oversight, in the long run," said Dr. Neil Hochstadt, professor of pediatrics at the University of Chicago Pritzker School of Medicine.
Such a permissive environment, if sustained, could open the door for future dangerous and addictive behavior.
"Young children are forming images of what they want to be, and when someone in a position of authority or control approves of drug use, I think there is a great concern for a future of addictive behavior," Farb said.
The concern could underscore the importance of foster care -- a situation which could last indefinitely until a suitable relative's home is found for the children.
"Intervention, education and putting these children in a different environment may later on give these children a good start," Farb said.
However, the lingering question of how often these children were exposed to illicit substances begs the biological question of whether damage has already been done.
A Recipe for Future Addiction?
Farb said that he is thus far unaware of any studies about the early age at which these children were exposed to marijuana and their future chances of abuse or addiction.
"Would exposure at a young age result in more profound biochemical changes in the nervous system?" he asked. "That's something that right now we can't answer with any certainty."
However, he said the ways in which drugs work on the brains of both young and old users create a worrying scenario.
Like many other illicit drugs, marijuana has chemical compounds that activate the reward center in the brain. Exposure to the drug could create a chemical "hook" that could lead to addictive behavior.
Even more worrying is the possibility that the videotaped episode was not the first instance of exposure for these children.
"Repeated exposure is an important factor," Farb said, adding that with marijuana, the effects may become greater with repeated use -- a process known as sensitization.
Additionally, there is some evidence that would suggest that exposure to drugs could have more of an impact on younger users. A previous study conducted by the Mayo Clinic in 2000 showed that children who have smoked only a few cigarettes experience the same symptoms of nicotine addiction as adults who smoke heavily -- suggesting that early exposure could have a significant impact on health later on in life.
Farb also notes that in studies of other psychologically active drugs -- such as those used to control anxiety -- the response of younger patients differs from that of adults.
While he said that this doesn't necessarily mean that the brains of children are more adversely affected than those of adults when it comes to marijuana, this possibility -- when combined with their prior living situation -- could create a recipe for addiction.
"These things can get coupled, so there are a combination of risk factors present," he said. "You have, if you will, the perfect storm of reinforcement in a child.
"It's bad enough for a child to be in an environment where the behavior is condoned," Farb said. "Add to that the exposure to the drug itself, and it is even worse."