Hurst analysis of EKG data obtained from a population of alcoholic (n = 13)
and nonalcoholic (n = 48) subjects was undertaken. Potential subjects (n =
120) were screened using the Schedule for Affective Disorders and Schizoph
renia and Structured Clinical Interview for DSM-III instruments. Data from
subjects with a diagnosis of current alcohol dependence were analyzed. Subj
ects with diagnoses such as major depression, bipolar disorder or schizophr
enia (Axis I diagnoses), or personality disorders (Axis II diagnoses) were
excluded from analysis. Subjects undergoing testing were free of alcohol an
d illicit drugs. Alcoholic subjects had no clinical evidence of alcohol wit
hdrawal symptoms at the time of testing. EKG data were obtained with eyes o
pen or with eyes closed. Approximately 3.5 min of data were obtained for ea
ch condition. Alcoholic subjects had less complex heart rate dynamics as ev
idenced by higher values of H = 0.18 +/- 0.05 (mean +/- SEM), compared with
healthy comparison subjects with H = 0.09 +/- 0.02, p < 0.014 for the eyes
closed condition, and H = 0.17 +/- 0.05 (mean +/- SEM) compared with healt
hy comparison subjects with H = 0.07 +/- 0.02, p < 0.011 for the eyes open
condition. A gender effect was seen, with female subjects showing evidence
of more complex heart rate dynamics than male subjects.