Anxiety states in elderly are often connected with different stress factors. One of the most common form of anxiety states is qualified as mixed anxiety and depressive disorder. Stress factors in elderly have their particularity. Anxiety states in elderly can develop in response to factors that wouldn’t cause mental disorders in a young persons. The most common chronic factors in elderly are lonely dwelling, change of life conditions and financial losses, diminished capacity of self-serving, helplessness and living in dependence of other people because of somatic diseases. Among acute stress factors could be mentioned on interrupted association with relatives, moving to a new place, had planned hospitalization and surgical treatment. Clinical picture of mixed anxiety and depressive disorder in elderly has its particularity. It is characterized by impairment of emotional and will functions expressed in depressive mood, fear, anxiety assessment of future. These factors lead to forming pathological motivation of behavior, accompanied by feeling of helplessness, uncertainty in abilities. Cognitive functions are also disturbed, especially in case of comorbide organic emotionally labile disorder of vascular genesis. In such cases symptoms of both disorders enforce each other. Firstly, attentive functions are disturbed because of fixation on unreal problems, connected with anxiety apprehensions. Voluntary memory is also reduced, especially on recent events. Although mixed anxiety and depressive disorder has a mild level of severity, it is accompanied with disturbance of critical functions. It has a great influence on persons’ capacity to make decisions and on level of social functioning.