There may be some unfortunate consequences for Lindsay Lohan in light of her failed drug test, but even with a slip in her sobriety so soon after leaving rehab, the fact that the actress fessed up to her indiscretion is a positive sign, an addiction expert told MTV News.

"From what I've heard, the tone with which Lindsay talked about the fact that she tested positive was very encouraging," said Robert J. Lindsey, president and CEO of the National Council on Alcoholism and Drug Dependency. "She really recognized that what this is is a relapse into active addiction, and she is very committed to making sure that she gets back on track."

Over the weekend, Lohan admitted to failing her recent drug test. Hours after reports surfaced Friday that the "Mean Girls" actress didn't pass her latest test, the troubled starlet conceded she was still struggling with addiction.

"Regrettably, I did in fact fail my most recent drug test and if I am asked, I am prepared to appear before judge Fox next week as a result," Lohan tweeted late Friday night. "Substance abuse is a disease, which unfortunately doesn't go away over night. I am working hard to overcome it and am taking positive steps forward every day. I am testing every single day and doing what I must do to prevent any mishaps in the future. ... This was certainly a setback for me but I am taking responsibility for my actions and I'm prepared to face the consequences."

Lindsey, who has no firsthand knowledge of Lohan's case, said her admission points to the value of doing drug tests. "Someone who is living in active addiction may not necessarily be able to tell you accurately what they have or have not done," he explained.

After wrapping up 13 days in prison and roughly three weeks in rehab, the actress was required to submit to random drug and alcohol tests, among other requirements, in order to avoid more jail time. According to the conditions of her post-rehab release, the actress could return to prison for 30 days if she fails a drug and alcohol test.

Another encouraging factor in Lohan's response to her positive test is the tone she took, which is quite different from the one she had in a recent Vanity Fair cover story, in which she appeared to be downplaying her addiction and deflecting blame for her troubles.

"The individual path to recovery varies for everyone," Lindsey said. "There are plenty of people who go into treatment and then NA or AA, and from that moment on, they never drink or use again. But the reality is that, for some people, they relapse back into active use, and it can be in some ways the best thing that ever happened. What it does is make very clear the fact that, 'I can't drink or use even a little bit without finding myself back in trouble again.' It can be a very powerful motivator for someone to become reinvested in treatment and recovery."