Effects of Wet and Dry Flotation REST on Blood Pressure and Plasma Cortisol

Abstract

Flotation Restricted Environmental Stimulation Therapy (F-REST) has been used successfully in the treatment of several stress-related disorders (Fine & Turner, 1982, 1985a; Rzewnicki et al., 1990; Koula et al, 1990). In F-REST (henceforth, REST) an individual lies supinely in thermoneutral buoyant fluid with minimal photic, auditory and tactile stimulation (Lilly, 1977). Deep relaxation reportedly accompanies REST (A. Barabasz, M. Barabasz, Dyer & Rather, 1990; Turner & Fine, 1983; Suedfeld, Ballard & Murphy, 1983). Relaxation has been shown to be associated with decreased activity of the adrenal axis (Davidson et al., 1979; Michaels, Huber & McCann, 1979; Jevning, Wilson & Davidson, 1978; McGrady et al., 1981). Plasma Cortisol can be measured as an indicator of this axis, and levels have been shown to decrease during REST (Turner & Fine 1983; McGrady et al., 1987). In addition, a decrease in blood pressure has been a common finding in previous REST studies (Jacobs, Heilbronner & Stanley, 1985; Fine & Turner, 1982; Kristeller, Schwartz & Black, 1982; Suedfeld, Roy & Landon, 1982), indicating that, along with plasma Cortisol, blood pressure can be a reliable index of the REST effect.