Changing one's pattern of breathing can influence the mixture of gases entering the bloodstream, triggering physiological effects as well as cognitive changes ranging from mild stimulation to panic. Methods for influencing consciousness through breath modification have been taught in some spiritual traditions for centuries. Since the 1960s, breathing modalities have been developed in the West to precipitate transformative or therapeutic states of mind. Holotropic Breathwork was specifically developed by Stan Grof to induce nonordinary states of consciousness without psychoactive drugs.
Forms of controlled breath that resemble asphyxiation can have fatal consequences. The "fainting game" or "choking game", sometimes engaged in by young people, is typically done by one person to another. Though its effects are sometimes described in terms of its psychoactivity, it can also be deadly.