We examined changes in serum levels of a selection of neurotrophic factors, TSH, HGH and cortisol in conjunction with ECT treatment. Fifteen patients suffering from affective disorders were included, all were treated with antidepressants and psychotherapy and 10 also with ECT. The patients were examined clinically and with blood samples during treatment. Serum levels of cortisol, thyroid stimulating hormone (TSH), nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT3), neuropetide Y (NPY) and human growth hormone (HGH) were studied. No significant changes were found in levels of NGF, BDNF, NT3, HGH and TSH. A change in NPY levels was statistically significant, but of uncertain clinical value as it affected only two patients. Levels of cortisol rose significantly during treatment. We did find significant correlations between the base values of NGF and HAM-D scores at inclusion and between the end-values of NT3 and NPY and the HAM-D scores prior to discharge. We were unable to reproduce findings from animal studies suggesting that a range of neurotrophic factors rise during ECT treatment. This may be because of physiological differences between animals and humans or, possibly, a result of the small number of patients included in this pilot study.