Article: In 1903 Hermann Emil Fischer and Joseph von Mering disclosed their discovery that diethylbarbituric acid, formed from the reaction of diethylmalonic acid, phosphorus oxychloride and urea, induces sleep in dogs. The discovery was patented and licensed to Bayer pharmaceuticals, which marketed the compound under the trade name Veronal as a sleep aid beginning in 1904. Systematic investigations of the effect of structural changes on potency and duration of action led to the discovery of phenobarbital at Bayer in 1911 and the discovery of its potent anti-epileptic activity in 1912. Phenobarbital was among the most widely used drugs for the treatment of epilepsy through the 1970s, and as of 2014, remains on the World Health Organizations list of essential medications. The 1950s and 1960s saw increased awareness of the addictive properties and abuse potential of barbiturates and amphetamines and led to increasing restrictions on their use and growing government oversight of prescribers. Today, amphetamine is largely restricted to use in the treatment of attention deficit disorder and phenobarbital in the treatment of epilepsy.

Question: Why was barbiturates and amphetamines restricted?
addictive properties and abuse potential