The answer to this question is yes... and no. It is important to first understand what psychoactive drugs actually are, because normally, the use of the word "psychoactive" often conjures images of hallucinogenic drugs like LSD. In actuality, psychoactive drugs are any drugs that impact the central nervous system, and that includes nicotine, alcohol, and even caffeine.
Now, the government certainly has put laws in place to limit nicotine and alcohol use. They implemented a minimum age to buy those substances and imposed severe criminal consequences for their abuse. Drunk driving and underage drinking, for example, can have significant legal ramifications. The law, however, does not place limits on one's right to buy and enjoy a cup of coffee. Caffeine is classified as a stimulant, as it impacts the central nervous system with heightened alertness and energy. Though it is a psychoactive (and addictive) drug, the government does not seek to limit its consumption.
Of course, other psychoactive drugs such as opioids, stimulants (like ecstasy), and hallucinogens are very much limited by the government. Illegal use of prescription pain relief drugs, for example, can have severe legal consequences, and hallucinogens like LSD are categorized as illicit (or illegal) drugs.