Actually re reading it I think the wording in the pscyosomatic medicine article is ambiguous and could be taken either way And as for ulcers did we ever actually think they were purely physical I was at least vaguely aware of the various components and the fact that some were still entirely unexplained but my wording was admittedly a little unclear As for stress and gene expression I was unaware of that and the wiki article makes no reference to it Can you provide details You ve got me curious