Neurasthenia
Neurasthenia (from Ancient Greek νεῦρον (neuron) 'nerve' and ἀσθενής (asthenés) 'weak') is a term that was first used as early as 1829 for a mechanical weakness of the nerves. It became a major diagnosis in North America during the late nineteenth and early twentieth centuries after neurologist George Miller Beard reintroduced the concept in 1869.