Mental energy
{{Distinguish|Energy (psychological)}}
Mental energy may be understood as the ability or willingness to engage in cognitive work.{{cite journal | vauthors = Lieberman HR | title = Cognitive methods for assessing mental energy | journal = Nutr Neurosci | volume = 10 | issue = 5–6 | pages = 229–42 | date = 2007 | pmid = 18284031 | doi = 10.1080/10284150701722273 | s2cid = 44452508 | url = }}
It is distinct from physical energy, and has mood, cognition, and motivation domains.{{cite journal | vauthors = O'Connor PJ | title = Mental energy: Assessing the mood dimension | journal = Nutr Rev | volume = 64 | issue = 7 Pt 2 | pages = S7–9 | date = July 2006 | pmid = 16910215 | doi = 10.1111/j.1753-4887.2006.tb00256.x | url = | doi-access = free }}{{cite journal | vauthors = Lieberman HR | title = Mental energy: Assessing the cognition dimension | journal = Nutr Rev | volume = 64 | issue = 7 Pt 2 | pages = S10–3 | date = July 2006 | pmid = 16910216 | doi = 10.1111/j.1753-4887.2006.tb00252.x | url = | doi-access = free }}{{cite journal | vauthors = Barbuto JE | title = Mental energy: Assessing the motivation dimension | journal = Nutr Rev | volume = 64 | issue = 7 Pt 2 | pages = S14–6 | date = July 2006 | pmid = 16910217 | doi = 10.1111/j.1753-4887.2006.tb00253.x | url = | doi-access = free }}{{cite journal | vauthors = Gorby HE, Brownawell AM, Falk MC | title = Do specific dietary constituents and supplements affect mental energy? Review of the evidence | journal = Nutr Rev | volume = 68 | issue = 12 | pages = 697–718 | date = December 2010 | pmid = 21091914 | doi = 10.1111/j.1753-4887.2010.00340.x | url = | doi-access = free }} Concepts closely related to mental energy include vigor and fatigue.
Mental energy is not well-defined, and the scientific literature on mental energy is quite limited. The philosopher and psychologist Karl F. Stifter wrote a dissertation on the "Philosophy of Mental Energy".{{Cite web |last=Stifter |first=Karl |date=2009 |title=Philosophie der Mentalenergie. |url=http://othes.univie.ac.at/5277 |website=Philosophisches Institut der Universität Wien.}} In the Austrian Broadcasting Corporation's TV show "Vera", Stifter lifted 1000 kg with a lifting belt over his sacrum to prove that drastic increases in muscle strength can be achieved after special mental training. ORF, TV-show „[https://der.orf.at/unternehmen/who-is-who/tv/fernsehstars-q-s/russwurm102.html Vera],“ 05.06.2003 A variety of measures for assessing aspects of mental energy exist.
Many people complain of low mental energy, which can interfere with work and daily activities. Low mental energy and fatigue are major public health concerns. People may pursue remedies or treatment for low mental energy. Seeking to improve mental energy is a common reason that people take dietary supplements.
Neurotransmitters
Many different neurotransmitters have been theoretically implicated in the control of mental energy. This has often been based on the effects of drugs acting on these neurotransmitters. These neurotransmitters include dopamine, norepinephrine, orexin, serotonin, histamine, acetylcholine, adenosine, and glutamate. Hormones, including glucocorticoids like cortisol, as well as cytokines, have also been found to regulate mental energy.{{cite journal | vauthors = Boksem MA, Tops M | title = Mental fatigue: costs and benefits | journal = Brain Res Rev | volume = 59 | issue = 1 | pages = 125–39 | date = November 2008 | pmid = 18652844 | doi = 10.1016/j.brainresrev.2008.07.001 | s2cid = 206344941 | url = https://pure.rug.nl/ws/files/31814601/Summary.pdf}}{{cite journal | vauthors = Jager A, Sleijfer S, van der Rijt CC | title = The pathogenesis of cancer related fatigue: could increased activity of pro-inflammatory cytokines be the common denominator? | journal = Eur J Cancer | volume = 44 | issue = 2 | pages = 175–81 | date = January 2008 | pmid = 18162394 | doi = 10.1016/j.ejca.2007.11.023 | url = }}{{cite journal | vauthors = Plihal W, Krug R, Pietrowsky R, Fehm HL, Born J | title = Corticosteroid receptor mediated effects on mood in humans | journal = Psychoneuroendocrinology | volume = 21 | issue = 6 | pages = 515–23 | date = August 1996 | pmid = 8983088 | doi = 10.1016/s0306-4530(96)00011-x | s2cid = 23244238 | url = }}{{cite journal | vauthors = Tops M, van Peer JM, Wijers AA, Korf J | title = Acute cortisol administration reduces subjective fatigue in healthy women | journal = Psychophysiology | volume = 43 | issue = 6 | pages = 653–6 | date = November 2006 | pmid = 17076823 | doi = 10.1111/j.1469-8986.2006.00458.x | url = }}
Food, drugs, sleep, diseases
=Drugs=
Drugs that may increase mental energy include caffeine, modafinil, psychostimulants like amphetamines and methylphenidate, and corticosteroids like hydrocortisone and dexamethasone.
Drugs that may decrease mental energy include sedatives and hypnotics like antihistamines, benzodiazepines, and melatonin, as well as dopamine receptor antagonists like antipsychotics.{{cite journal | vauthors = Bruno RL, Creange SJ, Frick NM | title = Parallels between post-polio fatigue and chronic fatigue syndrome: a common pathophysiology? | journal = Am J Med | volume = 105 | issue = 3A | pages = 66S–73S | date = September 1998 | pmid = 9790485 | doi = 10.1016/s0002-9343(98)00161-2 | url = }}
=Foods, beverages etc=
There are many marketing claims of foods, beverages, and dietary supplements improving mental energy, but data to substantiate such claims are limited or absent.{{cite journal | vauthors = O'Connor PJ, Kennedy DO, Stahl S | title = Mental energy: plausible neurological mechanisms and emerging research on the effects of natural dietary compounds | journal = Nutr Neurosci | volume = 24 | issue = 11 | pages = 850–864 | date = November 2021 | pmid = 31665988 | doi = 10.1080/1028415X.2019.1684688 | s2cid = 204968005 | url = }}{{cite journal | vauthors = Fernstrom JD | title = Diet, neurochemicals, and mental energy | journal = Nutr Rev | volume = 59 | issue = 1 Pt 2 | pages = S22–4 | date = January 2001 | pmid = 11255799 | doi = 10.1111/j.1753-4887.2001.tb01889.x | url = | doi-access = free }}
=Sleep=
Sleep deprivation may decrease mental energy in an exposure-dependent manner.
=Disease=
Various disease states, such as cardiac disease, cancer, stroke, HIV/AIDS, multiple sclerosis, Parkinson's disease, and certain mental health conditions like depression, may be associated with decreased mental energy. Chronic fatigue syndrome is characterized by a lack of the energy needed for the basic activities of daily life.