The last half-century, thanks to the efforts of outstanding researchers, brought about great progress in the pathogenesis and clinics of affective illnesses. The catecholamine and serotonin hypothesis delineated in the 1960s have retained significant merit. Since the 1990s, the theories have pointed on excessive immune activation and impairment of neuroplasticity under stress. Since the 1970s, asystematic subclassification of unipolar and bipolar affective disorder has proceeded. Epidemiological studies of the last half-century indicated a significantly higher prevalence of depression compared with previous decades. The 21st century brought evidence for agreater frequency of various forms of bipolar affective disorder. During the last 50years, the etiopathogenesis, diagnosis and treatment of affective disorders were my favorite and fascinating clinical and research topics. This initiated in 1970 when I began my work in the Department of Psychiatry, Medical Academy in Poznan, on account of the introduction of lithium salts for the treatment of these disorders. In 1976–1977, I received afellowship of the National Institutes of Health at the University of Pennsylvania in Philadelphia and participated in research that elucidated the mechanism of lithium transport across cell membranes. I carried out the studies on the pathogenesis of affective disorders for more than 40 years afterward. They concerned abnormalitiesof transport across cell membranes, the activity of stress system, excessive pro-inflammatory activation, molecular genetics, dysfunctions of cognition and neurotrophins, especially the brain-derived neurotrophic factor (BDNF). Atthe beginning of the 21st century, I coordinated two Polish epidemiological projects DEP-BI and TRES-DEP. For my research on bipolar disorders, I received many international awards. I am also the author of the book The faces of manic-depressive illness which had three Polish editions as well as English and Russian versions.