Long-term methadone treatment can cause changes in the brain, according to recent studies from the Norwegian Institute of Public Health. The results show that treatment may affect the nerve cells in the brain. The studies follow on from previous studies where methadone was seen to affect cognitive functioning, such as learning and memory.
Since it is difficult to perform controlled studies of methadone patients and unethical to attempt in healthy volunteers, rats were used in the studies. Previous research has shown that methadone can affect cognitive functioning in both humans and experimental animals.
Sharp decrease in key signaling molecule
Rats were given a daily dose of methadone for three weeks. Once treatment was completed, brain areas which are central for learning and memory were removed and examined for possible neurobiological changes or damage.
In one study, on the day after the last exposure to methadone, there was a significant reduction (around 70 per cent) in the level of a signal molecule which is important in learning and memory, in both the hippocampus and in the frontal area of the brain. This reduction supports findings from a previous study (Andersen et al., 2011) where impaired attention in rats was found at the same time. At this time, methadone is no longer present in the brain. This indicates that methadone can lead to cellular changes that affect cognitive functioning after the drug has left the body, which may be cause for concern.
No effect on cell generation