Bad trip (or psychedelic crisis) is a disturbing experience sometimes associated with use of a psychedelic drug such as LSD, Salvinorin A, DXM, mescaline, psilocybin, DMT and sometimes even other drugs including cannabis, alcohol and MDMA. The manifestations can range from feelings of vague anxiety and alienation to profoundly disturbing states of unrelieved terror, ultimate entrapment, or cosmic annihilation.
A multitude of reactions can occur during a psychedelic crisis. Some users may experience a general sense of fear or an anxiety attack. A user may be overwhelmed with the disconnection many psychedelics cause, and fear that they are going insane or will never return to reality. This can cause the user to fall into a depressive mood. Other reactions include an amplification of nameless fears; that is, fears that are unfounded and are usually not encountered in normality.
Users may exhibit actions suggesting harm to themselves or others around them. This harm could take the form of suicidal ideation, or full blown suicide attempts. Because of the magnification of emotions many psychedelics could possibly cause thoughts of death and intensely adverse reactions in some users. Users can believe that their death is imminent or that the very universe itself is collapsing.[3] Rapidly accelerated aging of other people may be experienced, perpetuating the aforementioned fears to an even greater degree.
Some users may experience disorientation. The normal views of time, space, and person can be substantially altered, causing fear. Some can worsen their condition by trying to fight the psychedelic experience after embarkment. There can be illusions of insects crawling over or into one's self, or of being in dirty places such as sewers.
In rare cases, an apparent complete loss of control can be observed, and the behavior a person exhibits reflects a lack of normal understanding about navigation of a physical environment. This can cause accidental harm to themselves and others, including running into traffic, flailing around, or, as it may not necessarily involve physical movement, inducing a catatonic state, or causing seemingly random vocalizations, not limited to speech. This may be caused by a failure to recognize external stimuli for what it is.