Anomalous stress reactions in patients suffering from depression and anxiety.

An experiment is reported in which the forearm muscle blood flow of a group of patients with mixed depressions is compared with that of a group of patients with anxiety states. The blood flow was measured under relaxed conditions and during the presentation of a noise `stress'. The measurements obtained under stressed conditions show that, while the blood flow of those with anxiety states fell with repetition of the stress noise, that of the depressive patients increased. A similar pattern was shown by the relaxed measurements but here the difference was not statistically significant. There was also suggestion that stress produced a fall in blood flow in depressive subjects and an increase in patients with anxiety states. These results tend to support the hypothesis that depressive patients show something akin to a freeze response to stress, while patients with anxiety states show an arousal response.