Women undergoing IVF show a high prevalence of depressive and anxiety symptoms. Furthermore, stress has harmful consequences on IVF and pregnancy outcomes. An immunological cascade was suggested to be involved in the process. Treatment in this setting is usually psychotherapy rather than pharmacotherapy, despite reasonable biological evidence suggesting beneficial influence of antidepressant therapy on pregnancy and well-being. Moreover, pharmacotherapy is more available and affordable than psychotherapy in the public health system. The investigators suggest to study the efficacy of antidepressant treatment in women undergoing IVF treatment, presenting with mild mood symptoms. The investigators hypothesize that treatment will result in a greater attenuation of affective symptoms, as well as in higher pregnancy success rates. Furthermore, certain immunological stress-reactive factors, may prove to be the biological mechanism underlying these effects.