Since 1987 several publications have focused on electrodermal reactivity in groups with different suicidal behaviors, but with varying results. However, using an untraditional statistical approach with clinical application in focus revealed between themselves confirming results of a strong relationship between electrodermal hyporeactivity and suicide.

The objectives were to investigate how this research tool can be implemented for detecting suicide risk in depressed patients.

The aims were to find a base for the objective test of electrodermal reactivity to be used as support in suicidal risk assessments in depressed patients.

More than ten published studies on electrodermal hyporeactivity and suicide were reviewed subsequent to the application of an untraditional statistical approach. Gender, age,

subdiagnoses and depressive depth were considered. All subjects were tested in a habituation experiment of the electrodermal response to a moderately strong tone stimulus.

The percentage of electrodermally hyporeactive depressed patients who later committed suicide was 86–97%. The percentage of electrodermally reactive patients that did not commit suicide was 96–98%. Hyporeactivity seems to be stable in at least 1–2 years in remission.

It was considered favorable to test for hyporeactivity as early as possible, i.e. already in the primary care. That enables right treatment of right patients very early. The number of referrals to psychiatric specialists could be expected to decrease. Possible causes of hyporeactivity begin to be revealed, giving ideas of several treatment approaches.

The author has not supplied his declaration of competing interest.