The malaise was dubbed 'Americantitis' by philosopher William James who suggested people were paying the price for America being so advanced. [dailymail.co.uk]

‘Review of the catalogue of Chinese herbal drugs showed that treatment of symptoms associated with neurasthenia was indicated in 10 patent drugs of Chinese herbs.’ [lexico.com]

[…] of personality characterized by hypersensitivity, introversion,self-consciousness, perfectionism and hypochondriacaldisposition.” 9 Morita therapy, which involves a period of mandatory rest and isolation and aperiod of progressively harder work, leading [ncbi.nlm.nih.gov]

[…] noun mass noun dated An ill-defined medical condition characterized by lassitude, fatigue, headache, and irritability, associated chiefly with emotional disturbance. [lexico.com]

Fatigue is the essential symptom for both diagnoses;others that overlap include muscle pain, headaches, inability to concentrate,irritability, and sleep disturbance. [ncbi.nlm.nih.gov]

'Physicians testified that, without a doubt, modern civilisation was causing a host of ills - everything from irritability to insomnia, lethargy to weight loss, anxiety to lack of ambition, and indigestion to impotence. [dailymail.co.uk]

Freud included a variety of physical symptoms in this category, including fatigue, dyspepsia with flatulence, and indications of intra-cranial pressure and spinal irritation. [6] In common with some other people of the time, he believed this condition [en.wikipedia.org]

It is listed as shenjing shuairuo, a condition“characterized by physical and mental fatigue, dizziness, headaches,other pains, concentration difficulties, sleep disturbance, and memoryloss.” 1 p48 The Tenth Revision of the World Health Organization's [ncbi.nlm.nih.gov]

[…] medical profession soon afterwards as Sigmund Freud shed more light on the way the body is connected to the mind DIAGNOSIS AND CURES FOR THE CONDITION From 1869, neurasthenia became a 'popular' diagnosis, expanding to include such symptoms as weakness, dizziness [dailymail.co.uk]

Eventually he separated it from anxiety neurosis, though he believed that a combination of the two conditions existed in many cases. [6] Diagnosis [ edit ] From 1869, neurasthenia became a "popular" diagnosis, expanding to include such symptoms as weakness, dizziness [en.wikipedia.org]

Three ofthe following five symptoms are required: “weakness” symptoms,“emotional” symptoms, “excitement” symptoms,tension-induced pain, and sleep disturbance. [ncbi.nlm.nih.gov]

The modern CCMD classifies it as a persistent mental disorder diagnosed with three of these five symptoms: "'weakness' symptoms, 'emotional' symptoms, 'excitement' symptoms, tension-induced pain, and sleep disturbances" not caused by other conditions. [en.wikipedia.org]

[…] lethargy, inertia, listlessness, lack of energy, lifelessness, inactivity, inaction, slowness, languor, languidness, torpor, torpidity, dullness, heaviness, apathy, passivity, weariness, tiredness, lassitude, fatigue, sleepiness, drowsiness, enervation, somnolence [lexico.com]

‘In case after case, from somnambulism to neurasthenia to ‘Yuppie flu,’ we see how medical and cultural trends alternately reinforce and erode particular psychosomatic symptoms.’ [lexico.com]