Althea smokes heroin in her friend's car before she is taken to rehab in Southern California.

After going through rehab in Southern California and sustaining sobriety for more than six months in sober living, Althea relapses and begins to use heroin again.

Althea estimates that she injects a gram of heroin a day. She also has begun to use meth recreationally. She says she likes the extreme highs and lows, but hates how it makes her skin look.

Relapsing again, Althea went to live with her friend, Jared, in Santa Monica. After several weeks of using in secret, Althea was given an ultimatum from Jared: go to rehab, or be homeless. In the emergency room, Althea started coming off of her high and was frustrated it was taking so long to be put on other drugs to help her deal with the pain that comes with withdrawal. Earlier in the day, Althea and Jared got into a fight and she ran away in search of heroin. Forgetting her phone at Jared's apartment, Althea wrote the only two phone numbers she knew by heart on her hand, afraid she would forget once she got high.

One week since her last injection of heroin, Althea is taken care of by her mother in Vermont. "These were the worst withdrawals I ever had," Althea said.

Althea spent nearly a week bedridden and unable to leave her house. She struggles to walk even a block without pausing to catch her breath. She says she is frightened for the future and doesn't know if she can stay sober. In the mirror's frame sits a photo of Althea and me.

Althea finds it increasingly difficult to be sober. She wants to use but knows that her family would put her on the street if she did.

Althea finds she can't stay sober, despite the methadone injections she gets on weekdays.

Body image plays a role in why Althea uses. She sometimes uses heroin as a way to stay thin.

Althea always looks forward to spending time at her grandparents' summer home in the Adirondacks. She enjoys being with her family, even though she feels that many judge her for her drug use. Althea often expresses a desire to return to childhood, where life seemed simpler for her.

Finding it difficult to interact with others her age, Althea ostracizes herself in social situations.

Althea continues to try to hide her heroin use from her family and friends. She has developed a close relationship with her mother and spends most of her time with her.

As part of a new ritual, Althea uses heroin at her home. She says that her addiction is now manageable because she doesn't use during the week and is able to keep her job.

Despite her relapses and continued use, Althea wants to get sober. After almost overdosing several times, Althea is beginning to see the effect that the drugs are having on her and her mother. She wants to try sobriety but isn't sure she can succeed.

One week since her last injection of heroin, Althea is taken care of by her mother in Vermont. "These were the worst withdrawals I ever had," Althea said.