Over the past twenty years the functional brain imagenology has improved a great. Today the diagnostic, prognostic and therapeutic response are possible in psychiatry and neurology. The functional denomination in psychiatry has been known for more than a 100 years and it can be evident in the brain images. The relation between the blood brain flux and the brain can be seen as pictures in the Brain Spect as hyper and hypo function areas. To carry out Spect a venous injection of Tc-99m Tenneco and (HMPAO) or (ECD) is applied in the arm. The images show the brain function since the until two minutes later. The exam can be done until six hours after the brain fixation. The study is carried out in conditions, with the patient in repose, relaxed and without medication. The final result is an brain in colors. The yellow color gives us 95% of decrease and white color 95% of increase of the brain function. The red color gives a normal perfusion. The object of the study is to find that the Brain Spect could be used as a new diagnostic marker of depression. The sample was 73 outpatients with major depression. Our diagnostic marker is the prefrontal cortex ventral hypoperfussion (orbit frontal) in almost 100% of the patients and only 32% dorsal hypoperfussion (executive area), unlike almost authors.