A study of nearly 4,000 teenagers published online in the Journal of Epidemiology and Community Health, shows that secondary school children who take methamphetamine (speed) and MDMA (ecstasy) appear to be prone to depression later on. The study results proved to be independent of previous bouts of depressive symptoms or other drug use.Speed and ecstasy first gained popularity amongst clubbers and people in the rave scene. However, both drugs have also become increasingly popular in the general population, such as secondary school children, who, according to the researchers, often take both drugs at the same time. Because of increasing concerns that these synthetic drugs could cause long-term neurological damage, particularly in those where the brain is still being developed as in adolescence, ?the researchers decided to conduct a study ?by tracking the mental health of a sample of 3,880 secondary school children of disadvantaged areas in Quebec, Canada between 2003 and 2008. At age 15 to 16 years, i.e. grade 10, the students were surveyed about their ecstasy and speed consumption. A year later, in grade 11, the researchers assessed the students\' mental health by using a validated scale. ?? The survey revealed that speed seemed to be more commonly used, with 451 students or 11.6% admitting to have taken speed, whilst 310 or 8% of the participants admitted they consumed ecstasy whilst in grade 10. One year later, the researchers observed that one in seven, or 15% of teens, scored at the upper end of the CES-D scale for depressive symptoms, reaching a score of 16 or more. ? The researchers accounted for previous depressive symptoms and other drug use, and found that those who used either drug had a 60 to 70% higher likelihood of experiencing elevated depressive symptoms, compared with those who used neither drug. The 6.7% of the students who reported to have used both drugs were nearly double as likely to experience elevated depressive symptoms compared with those who did not use any drugs. The researchers suggest there are \"additive or synergistic adverse effects of concurrent us,\" adding that these findings support those of previous studies into long-term using of synthetic drugs. They say: \"Our results provide, to the best of our knowledge, the first compelling evidence that recreational [ecstasy] and [speed] use places typically developing secondary school students at greater risk of experiencing depressive symptoms.\" ? ?They conclude that this type of drug use has a \"relatively modest\" contributing factor on depression, but warn: \"Modest contributions can have significant clinical implications from a population health perspective.\"?? The highlight the need for further research to determine whether these symptoms are caused by neurological damage and whether a developing brain is particularly vulnerable to the impact of synthetic drugs.