Relationships between fatty acids and psychophysiological parameters in depressive inpatients under experimentally induced stress

Fatty acids can influence important cellular and hormonal processes in the human body. Non-adequate contents of fatty acids, e.g., in blood, can cause and/or result in various diseases. In depressive patients, changes in fatty acid concentrations were found (deficits in omega3-fatty acids, in particular). This paper poses the question whether there are any relations between psychophysiological parameters and changes in fatty acid compositions. The concentration of fatty acids in serum of 118 psychiatric inpatients measured directly before and after experimentally induced stress of about 1h were analysed in relation to psychophysiological parameters continuously registered during the experimental sessions at admission, discharge and at 3 months follow-up. Systolic and diastolic blood pressure, finger pulse amplitude, forehead temperature (FD) and the EMG activity of the musculus zygomaticus consistently correlated with concentrations of single unsaturated oleic (18:1n-9) and erucic acid (22:1) and saturated myristic (14:0) and lauric acid (12:0). Negative relations were found between FD and the concentration of arachidonic acid (20:4n-6) as well as of palmitoleic acid (16:1). Furthermore, the higher the concentration of the erucic acid at discharge the higher the depression score as assessed by the Beck depression inventory (BDI). High concentrations of palmitoleic acid and lauric acid were related to a low level of depression (BDI and Hamilton scores). The implications of these findings for add-on treatment regimens in depression are discussed.