It takes time, but the brain can recover.
This image shows PET scans of dopamine transporter (DAT) binding in three brains: (1) a healthy control (top); (2) a methamphetamine abuser one month after discontinuing drug abuse (middle); and (3) a methamphetamine abuser after 14 months of abstinence (bottom). The control brain shows a robust concentration of dopamine transporters in the striatum (red and yellow), while the methamphetamine abuser has a dramatic drop in DAT binding, even a month after drug abuse has stopped. Sustained abstinence, however, allows a near-full return of DAT binding to normal levels. Still, some of the behavioral effects of methamphetamine do not completely return to normal (not shown). This means that it can take a long time to recover from methamphetamine abuse, but recovery is possible.
As a result of scientific research, we know that addiction is a disease that affects both brain and behavior.