HRV Time and Spectral Components:
Analysis of circadian heart rhythm provides objective indications of physiological differences between different forms of mental illness.
Mental state-linked autonomic nervous system disturbance (biological shifts) are observed during sleep when external influences are absent.
Distinctly different patterns are evident during sleep when confounding influences on heart rate are minimal.
Digital biomarkers are relevant to circadian processes.
"We will no longer endorse DSM5, as it has fundamental flaws and we are actively seeking a diagnostic system that is evidence based. We need a quantitative method for diagnosing depression. It is critical to realize that we cannot succeed if we use DSM categories as the gold standard."
U.S. National Institute of Mental Health May 2013