In depression and schizophrenia, structural changes occur in the brain. In schizophrenia and depression, there is an increase in the white matter of the brain and a decrease in gray matter. The changes concern:
- middle temporal gyrus;
- prefrontal gyrus;
- left ventral medial gyrus;
- left lingual gyrus;
- dorsal medial prefrontal gyrus.
The left temporal gyrus functions as a second sensory cortex. When its structure and neurotransmitter activity are disturbed , the processing of sensory information changes. Symptoms of this are seen in patients with depression and schizophrenia. Sensory processing affects the affective sphere, which leads to mood disturbances. Therefore, there is a connection between schizophrenia and depression. Defects in secondary sensory processing are associated with emotional dullness, rejection, hallucinations, and abnormal sensations.
The frontal cortex is responsible for executive control. Violations in this area lead to a decrease in cognitive functions, attention, control, behavior. Cognitive and executive activity suffers.
Depressive disorders, like no other disease, are determined by genetic factors. This is especially true for bipolar disorder.
The risk of developing mood disorders is high in first-degree relatives. In 1982, Winokur identified three types of unipolar depression based on family history:
- Familial depression with a family history.
- Depression with a family history of alcohol abuse and antisocial personality disorder.
- Episodic familial depression with negative family history.
Currently, 15 different genes have been found that are responsible for the development of depression, they affect the nucleotide sequences encoding the nerve growth factor, the catechol- O- methyltransferase gene, the DISC1 gene, disrupted in schizophrenia, the genes encoding dopamine receptors responsible for the functioning of the serotonergic system, and beta -2-adrenergic receptors.
The diagnosis and treatment of depression and schizophrenia must move to a new level of understanding of the organic and genetic factors in the development of these diseases, which will facilitate effective therapy.