LSD quickly became a popular drug outside of the medical profession. Many people began using or giving LSD out casually. "Acid parties" and "acid tests" became a social fad. The drug would sometimes be slipped to persons unknowingly, often through "spiked" punch or drinks. Some problems developed, as some casual users began to experience side effects, such as "flashbacks" and psychotic symptoms, though both of these are rare. Sometimes signs of depression and instability were seen. Due to the spread of LSD use outside of the medical community, the United States government banned LSD (made it against the law to make, have or use) in 1967. Other countries soon followed.