Because alcohol was a common co-substance for nearly all of the people in the polysubstance use group, it was difficult to tell exactly which substances were affecting certain cognitive functions. The researchers found that the difference in the two groups performance levels on executive function, or higher-level cognitive processing tasks were consistently showing that the polysubstance group scored lower than the control group. In general, this meant that multiple substances negatively affected the polysubstance groups cognitive functioning. More specifically, the researchers found that the amount of cannabis and cocaine affected the verbal part of working memory, the reasoning task, and decision making, while cocaine and heroin had a similar negative effect on visual and spatial tasks, but cannabis particularly affected visual and spatial working memory. These results suggest that the combined use of cannabis, cocaine, and heroin impair more cognitive functions more severely than if used separately.Alcohols negative effects on learning, spatial abilities and memory has been shown in many studies. This raises a question: does using alcohol in combination with other substances impair cognitive functioning even more? One study decided to try to determine if people with polysubstance use who also recreationally use alcohol would display poorer performance on a verbal learning and memory test in comparison to those who consumed excessive amounts of alcohol specifically. The California Verbal Learning Test (CVLT) was used due to its ability to "quantify small changes in verbal learning and memory" by evaluating errors made during the test and the strategies used to make those errors.
Sinecatechins (USAN, trade names Veregen and Polyphenon E) is a specific water extract of green tea leaves from Camellia sinensis that is the active ingredient in an ointment approved by the FDA in 2006 as a botanical drug to treat genital warts. Sinecatechins are mostly catechins, 55% of which is epigallocatechin gallate. It was the first botanical drug approved by the US FDA. == References ==