The 600-million-year history of human affective disorder

Barbara Natterson-Horowitz

Division of Cardiology, UCLA School of Medicine

Department of Ecology and Evolutionary Biology, UCLA

Department of Human Evolutionary Biology, Harvard University

Department of Global Health and Social Medicine, Harvard Medical School

Fifty years ago this October, the Nobel Prize in Medicine was awarded to three animal behaviorists based on the belief that the emerging field of ethology could transform our understanding of human biobehavioral health. Unfortunately, the promise was not realized within the lifetimes of the scientists themselves. In the decades that followed, advances in biological psychiatry challenged psychoanalysis as the singular source of explanatory insights into mental illness. Regrettably, highly reductive biological approaches that lack a broader, integrated organismal and ecological context have not led to much needed transformational knowledge.

Today, broadly comparative and ecologically-informed studies of animal behavior are revealing: 1) the ancient origins of human affective systems and affective disorders in the social brain networks of early social animals, 2) the important links between brain biology promoting adaptive behavior in chronically subordinated animals and neurovegetative symptoms in depressed human beings, and 3) evidence that withdrawn behavior, anhedonia, and reduced cognitive and motoric activity in chronic subordinates increases survival in certain individuals. Recent studies connecting social defeat to severe depression point, once again, to animal behavior as a source of insights into human mental health. In fact, phylogenetic perspectives can provide much needed scaffolding on which to layer, with context, the rapidly growing body of reductive knowledge about the human brain in health and illness.

Dr Natterson-Horowitz’s lecture will first survey the historical and scientific settings in which both insights were recognized and overlooked. She will then present an up-to-date summary of insights into human affective disorders emerging at the intersection of behavioral ecology, neurobiology, psychopharmacology, and evolutionary biology.