On the point of view of systemic approach we consider that non- psychotic mental disorders are developing on the basis of both organic and adaptation levels. According today investigations psychiatrists distinguish both psychological and intrapsychic levels of adaptation. The task of our work was to investigate mechanisms of psychological defense in patients with primary hypothyroidism with non-psychotic mental disorders. Totally 132 patients with primary hypothyroidism patients were ranged. 108 patients accounted for 81,12% of the total number of monitored, was to provide various forms of non-psychotic mental disorders: astheno-depressive (32,41), asthenic (27,78%) and astheno-anxious (18,52%). In 23 patients (12,04%) anxiousdepressive syndrome, and 10 (9.25%) developed hypochondrical syndrome. In the study the adopted method of assessment typology of psychological defense was used. In asthenic syndrome we found excessive functioning of negation and regression, inadequate functioning of intellectualization. In patients with astheno-anxious syndrome inadequate functioning of negation, intellectualization, compensation, and excessive repression contributed to the formation of the sensations of anxiety. Excessive compensation, projection, reactive formation generally affected the structure of the asteno-depressive syndrome. The lack of displacing of reactive formation, repression and excessive intellectualization in a complex influenced to the structuring of anxious-depressive syndrome. In hypochondrical syndrome projection, regression and negation were the basis of the formation of clinical picture. Thus, meaningful relationships between intrapsychic level of functioning and syndromological structure of non-psychotic disorders were installed and highlighted the basic mechanisms of protection, that affect the formation of a clinical picture.