OBJECTIVE To specify forms of severity of mental disorders in neurocirculatory asthenia (NCA) for more precise differentiation between NCA as a nosological entity and syndrome. METHODS The examination including specially-designed interview, ECG, echo-CG, orthostatic and hyperventilation tests, bicycle exercise, consultation of the psychiatrist, psychological tests covered 80 NCA patients (31 men, 49 women, mean age 29.2 +/- 9.08 years). RESULTS NCA is characterized by the absence of a clear link with psychoemotional stress, seasonal disease aggravations, weakness, dizziness, negative results of orthostatic and hyperventilation tests. Among NCA criteria, dominating are "additional signs". Patients with anxio-fobic, panic, anxio-depressive neurotic disorders are characterized by strong relations between manifestation, subsequent disease exacerbations with psychogenia; attack-like NCA manifestation, prevalence of "basic signs" among diagnostic criteria (cardialgia, pulse and blood pressure lability, nonspecific alterations of T wave, positive orthostatic and hyperventilation tests). CONCLUSIONS NCA presents at least with two variants. In the first variant NCA picture is characterized by hereditary or early acquired vegetative stigmation and secondary neurotic disorders; the second variant presents as a clinically formed illness in which NCA symptoms manifest as a syndrome which is a leading component of a mental disease.