There are pain relieving trances and pain producing trances. There are healing trances and pathological trances. To many psychologists a trance is a state of limited awareness. Some psychologists would also characterize trance as a form of sleep, or dreamlike awareness or a kind of altered state of consciousness. Certainly trance has long been associated with hypnotic states, and with the altered states of consciousness of dervishes, shamans and yogis.
Meditation does produce strong trance states.
However, in my opinion, trance states are much more common than is normally believed. If the unusual trance state of a shaman or a yogi is desirable, then we might be tempted to believe that all trance states are desirable states. The type of trance studied most has been the hypnotic trance. Milton Erickson, the great psychotherapist, had wonderful and nearly immediate psychological cures in a great many of his patients. Many people tried to explain what it was that he did, because in many cases, his patients claimed that they were not hypnotized and they were not in any kind of trance at all.