Bad trips are more common at high doses, where the psychedelic effect is more intense, and in unfamiliar environments, where anxiety and paranoia are more likely to arise. Bad trips can also be exacerbated by the inexperience or irresponsibility of the user or the lack of proper preparation and environment for the trip (known as "set and setting"). At the extreme, the occurrence of bad trips without proper preparation can result in a tripper committing self-harm or harming others, suicide attempts and contact with law enforcement. For this reason, a person who plans on taking a psychedelic is often accompanied by a trip sitter.