small inclinations towards mood disorder, depression and tobacco are some of things the Neanderthals are believed to have contributed to Europeans and Asians. Not saying this as a downer but as some of the things that may have been encountered and resisted as well as making contributions to culture, politics and the building of an economy. edit: apparently they lived in N. Africa, across central and Northern Asia and may even have lived in China and Mongolia as well as Europe!!
http://psychnews.psychiatryonline.org/doi/full/10.1176/appi.pn.2016.3b22
Neanderthals had lived in Europe and Asia for hundreds of thousands of years and so were well adapted to a colder climate and its pathogens. Offspring of the two populations thus might have been slightly better adapted in some ways to that environment, preserving Neanderthal DNA in the genome of modern humans.
Capra’s team compared high-resolution maps of Neanderthal haplotypes with data on 28,416 present-dayhumans from the Electronic Medical Records and Genomics (eMERGE) Network, a consortium linking genetic and medical diagnostic data from patients in seven academic medical centers across the United States.
Using genomewide complex trait analysis, they found significant but small contributions to risk of actinic keratosis (2.49 percent), mood disorders (0.68 percent), and depression (1.06 percent) from the Neanderthals. The Neanderthal alleles are enriched near genes known to be associated with depression, wrote Capra and Simonti.
A second approach, a phenomewide association study, also found associations with hypercoagulable state and tobacco use disorder.
The latter finding had nothing to do with tobacco, a New World plant. Rather, it is connected to a single-nucleotide polymorphism involved with reuptake of the neurotransmitter γ-aminobutyric acid (GABA).