They may exhibit dramatic mood swings, going from extreme happiness to deep depression. Minor events, such as the sun going behind a cloud, can trigger these mood swings. Users may also laugh at times of sadness or cry during happy occasions. Tolerance disappears quickly when use is stopped. Flashbacks, or the re-experiencing LSD's effects, can occur without warning for up to a year or longer after use.
Flashbacks are most likely to occur among frequent users.
Flashbacks occur at any time or place and may be initiated by stress or the use of other drugs. The reason flashbacks occur is unknown. The user feels in extreme danger. These scary sensations may last a few minutes or several hours. The user experiences confusion, anxiety, panic, suspiciousness, a feeling of helplessness and a loss of control.