Soma in Brave New World is said to be better than promiscuous sex, the only sex that is offered that the population can practice. This enjoyment causes the populous to build up a dependence upon the drug. In this world they have become so dependant upon soma at anytime where unpleasant thoughts, feelings or emotions are shown, they just drive them out with soma, this is shown in the reoccurring saying that, One cubic centimeter cures ten gloomy sentiments. The reason people in Brave New World resort to soma when ever feel depressed, angry or have disturbing pessimistic thoughts, is because their lives, like their society, are empty of spirituality or any higher meaning. Soma causes the population to be happy with their fate. Soma also causes a physical dependence, rather than mental, for example when a frequent user of soma, runs out they become sick. This fate is shown when Lenina is visiting the Savage Reservation and run out of soma she becomes ill. This dependence and inability to function metal and physical with out soma allows the government to control the population completely and allow them to love their fate. This regiment of soma doesn't deliver anything inspirational or life enriching. It doesn't enhance any emotional epiphanies, intellectual breakthroughs or life defying insights. It doesn't promote physical or personal growth. Instead it just provides a false mindless happiness. It is as unintelligent escapism which allows people to be accepting and comfortable with their lack of freedom. Soma is a narcotic that raises an impenetrable wall between the actual world they live in and their minds. 1984 is not controlled as much by drugs or pleasure but it is done through the manipulation of language and thought.
In Huxley's Brave New World, genetic engineering is rampant from birth. This technology is used to enhance future Alphas or to cripple the impending Epsilons. This class structure and the genetic engineering used to create it is a major control device for the people in Brave New World.