Hereditary diseases exist everywhere, occurring in the form of cycles lasting up to several months or more. In modern classifications, two types of the disease occur: monopolar depression, or depressive disorder, in which only endogenous depression develops, and bipolar disorder, in which manic phases develop, often followed by depression. Cases of manic episodes without depression are well known, but are rare. A depressive episode can develop without provoking factors, although it is often preceded by stressful situations or the loss of a loved one within a few months. The patient experiences depression, sadness or decreased mood, deep pessimism and a sense of hopelessness. Along with affective disorders, there is a loss of interest in all matters and feelings of pleasure, decreased performance, mental and physical fatigue, sleep disturbance (often with early morning awakenings), loss of appetite, weight loss, weakened sex drive and various pains, including headaches . Many patients, especially the elderly, develop agitation and anxiety, while others experience psychomotor inhibition. Typical signs of depression include self-abasement, a sense of personal worthlessness and guilt, suicidal thoughts, excessive fixation on somatic diseases (dermatological, rheumatological, etc.). Expressed complaints of worsening physical well-being or memory impairment may be mistakenly regarded by a doctor as manifestations of latent somatic disease or early dementia. Manic episodes are characterized by an increased background of mood and activity (excessive volume and speed of speech production, as well as all forms of psychomotor activity). With euphoria, the need for sleep is reduced. In severe manic states, inconsistent thinking is possible. The patient has many plans, but not one of them is fully implemented. Criticism is reduced or absent. The patient loses the ability to critically evaluate his own problems; inappropriate actions are possible with negative consequences for social status and material well-being. Despite increased activity and expansiveness, tolerance to frustration is often reduced, and euphoria is combined with irritability. In some cases, distinct paranoid symptoms and aggressiveness are formed. A particular problem is patients with schizoaffective conditions – a combination of symptoms of depression and schizophrenia. It has been proven that most of these patients suffer from manic-depressive psychosis. According to most neurologists and psychiatrists, genetic factors play the most important role in the etiology of manic-depressive illness, although the provoking effect of stress and other environmental changes is not ruled out. The high frequency of monopolar and bipolar disorder in the families of patients, as well as the 75% level of concordance in monozygotic twins confirm the genetic basis of the disease. Attempts to study pathogenesis based on measurements of serotonin, adrenaline, corticosteroids, dopamine and other metabolic products have not yet led to convincing results. At the present stage, in the management of patients with depression, drugs are successfully used. In monopolar depression, serotonergic or tricyclic antidepressants are usually used as first-choice drugs. Serotonergic drugs are more preferred as they cause fewer side effects. If these antidepressants are not effective, then MAO inhibitors are used. In acute manic conditions, it may be necessary to prescribe antipsychotics (haloperidol, torazine, olanzapine), and lithium carbonate can be used to prevent them. Approximately 20% of patients do not help the above medicines. In such cases, other drugs are used under the supervision of an experienceda psychiatrist. A sufficiently long medication may be required – several weeks before the onset of a clear effect and an additional 6 to 12 months of maintenance therapy. When prescribing any of these drugs, you need to know their side effects and interaction with other drugs well. Electroconvulsive therapy (ECT) is used to treat patients who do not respond to or tolerate antidepressants. ECT is the most effective method for the treatment of agitated and catatonic depression in patients of middle and old age; it can also be used to interrupt a manic episode. The main side effect of ECT is memory impairment, usually short-term. ECT is contraindicated in cases of increased intracranial pressure or severe hypertension.