A method for diagnosing a psychiatric disorder in a subject, the method comprising the steps of: measuring the pattern of a subject's biophysical parameter and using said pattern to diagnose the psychiatric disorder. It has been found that certain clinical states are consistently associated with distincly different patterns of biophysical parameters. Norm al and abnormal profiles are established, and subjects are tested by monitoring the pattern of a given parameter and comparing said pattern wi th reference patterns indicative of a psychiatric disorder. Heart rate is one biophysical parameter that can be readily and conveniently measured. Psychiatric disorders may be identified and diagnosed from analysis of characteristic patterns within portions of the circadian heart rate pattern. In one particular form, the heart rate pattern is measured over a period of at least approximately 90 minutes. The portion of the circadian heart rate pattern is preferably the sleep portion and in particular the sleep portion including the transition of the subject into and out of sleep. Preferably, the subject's heart rate is measured with a monitor that is unobtrusive and leaves the person freely ambulant. Heart rate patterns may be affected by a range of factors. Some factors may produce noise that may hamper the interpretation of the heart ra te pattern. Comparison of the subject's heart rate pattern with the record of the subject's activities allows for the effects of noise in th e subject's heart rate pattern to be negated.
METHOD FOR DIAGNOSING PSYCHIATRIC DISORDERS