Pathophysiological and neurobiological basis for the development of depression in patients with Parkinson’s disease

Parkinson's disease (PD) is one of the most common neurodegenerative diseases, second only to Alzheimer's disease. PD is characterized by multisystemic lesions and steady progression of the pathological process, which inevitably leads to the occurrence of various symptoms. PD symptoms are divided into motor and non-motor. It is generally accepted that non-motor symptoms precede motor ones and appear several decades before motor symptoms. The most common non-motor symptom of PD is depression, which significantly reduces patients' quality of life. The review addresses recent studies of the pathophysiology of depression in PD patients. The analysis showed the involvement of the substantia nigra, the raphe nuclei, and the locus ceruleus in the development of depression in PD patients. The molecular basis of their dysfunction is a deficiency of dopamine, serotonin, and norepinephrine. A detailed study of the neurobiological mechanisms of the development and progression of depression will create highly effective and pathogenetically based therapeutic areas.