Charles Darwin (1809-1882) suffered from a chronic illness that, throughout much of his adult life, impaired his functioning and severely limited his activities. The writings of this famous scientist as well as biographical materials indicate that he probably suffered from an anxiety disorder. His symptoms, when considered individually, suggest a variety of conditions, but taken together they point toward panic disorder with agoraphobia. This diagnosis brings coherence to Darwin's activities and explains his secluded lifestyle, including difficulty in speaking before groups and meeting with colleagues. JAMA. 1997;277:138-141

CHARLES DARWIN (1809-1882) suffered from a chronic illness that impaired his functioning and altered the course of his life. His symptoms involved many organ systems, but anxiety was especially prominent.1As a young man he had episodes of abdominal distress, especially in stressful situations.23 Later, he experienced cardiac palpitations and chest pain in anticipation of his voyage on the Beagle.4(PP?98) During his travels, Darwin remained well, although seasickness was a recurrent problem. Even after his return to England, he led a vigorous life, presenting papers at various societies, attending meetings, and writing a travel narrative.5 However, at the age of 28 years he began to experience attacks of fear. Describing them, he said, "I have awakened in the night being slightly unwell and felt so much afraid though my reason was laughing and told me there was nothing and tried to seize hold of objects to be frightened of."6 Throughout the remainder of his life, he experienced recurrent attacks accompanied by a variety of physical and emotional symptoms including palpitations, shortness of breath, lightheadedness, trembling, crying, and abdominal distress. This illness was present during the 22-year period when Darwin was writing On the Origin of Species (published in 1859).

Darwin was attended by physicians who considered "dyspepsia with an aggravated character," "catarrhal dyspepsia," and "suppressed gout."7-9 Based on available information, historians suggested a variety of diagnoses from arsenic poisoning to neurasthenia From the writings of Darwin himself, as well as biographical materials, we conclude that he may have suffered from panic disorder with agoraphobia. Panic disorder is a chronic illness characterized by sudden attacks of fear accompanied by somatic symptoms such as palpitations, dizziness, and shortness of breath.lo Agoraphobia, a variant or complication of this disorder, is an unreasonable fear of situations from which escape might be difficult or help unavailable in case of incapacitation (ie, a panic attack). This fear leads to avoidance of situations such as crowds, travel, and being alone. Panic disorder can impose severe restrictions and have a devastating impact on a person's life. To our knowledge, this diagnosis has not been previously suggested as the explanation for Darwin's symptoms.

A great deal has been written about Darwin's illness, much of it by the great man himself, and from many sources a rather complete description of his condition may be pieced together. To obtain a full picture, we abstracted Darwin's personal reflections from notebooks, letters, and diaries. We also consulted Darwin's autobiography,4 his published correspondence, several recent biographies, and 2 volumes of his letters, published posthumously by his son, Francis Darwin.11-15 These materials show that Darwin began mentioning health problems as early as 1825 and continued to write about them until late in life.

DARWIN'S ILLNESS

In descriptions of his illness, Darwin frequently referred to discrete attacks that began suddenly and left him drained. For example, he referred to "many bad attacks of sickness," and Dr Edward Lane, a personal physician, twice used "attacks" when writing about Darwin's illness.ls These attacks consisted of palpitations, shortness of breath ("air fatigues"), lightheadedness ("head swimming"), trembling, crying, dying sensations, abdominal distress, and depersonalization ("treading on air and vision"). Such symptomatic surges were very disruptive, as Darwin said, "[C]onstant attacks . . . makes life an intolerable bother and stops all work."17 Darwin's accounts contain numerous references to typical panic symptoms during attacks. For example, writing in his journal he described himself as, "[u]nusually unwell, with swimming of the head, depression, tremblingand many bad attacks of sickness."18 In a letter to his friend and confidant Joseph Hooker, he added, "My nervous system began to be affected so that my hands trembled and my head was often swimming,"19 and in another letter, he noted, "[i]nvoluntary twitching of the muscle. . fainting feeling-black spots before eyes."20

In various letters, Darwin described additional panic symptoms. Late in 1837, while formulating his theory of evolution, he wrote to his Cambridge teacher Professor John Henslow, saying, "I have not been very well of late with uncomfortable palpitations of the heart."21 The same year he again wrote to Henslow and cited ill health as one of the reasons for refusing the secretaryship of the Geological Society, with the comment, "Of late, anything which flurries me completely knocks me up afterwards and brings on violent palpitation of the heart."2 When Darwin was in his mid 50s, he recalled in a letter to Dr John Chapman many years of "treading on air and vision" suggestive of depersonalization. Additionally, he noted "air fatigues, especially risky, bring on head symptoms."3 His description sounds like shortness of breath or hyperventilation leading to dizziness and lightheadedness. In the same letter, he describes a 25-year history of "hysterical crying, dying sensations and half faint."23

Gastrointestinal symptoms were also prominent. For instance, in turning down an invitation to Delamere, he told his Cambridge friend and cousin William Fox, who was rector of Delamere in Cheshire, "I dread going anywhere, on account of my stomach so easily failing under any excitement."(l" In a letter to Joseph Hooker, he related difficulty after speaking briefly to the Linnean Society. He said, "I never felt my weakness a greater evil . . . I spoke a few minutes . . . and it brought on twenty-four hours of vomiting.'" Dr Edward Lane, Darwin's personal physician, suggested, "Mr. Darwin was . . . a great sufferer of dyspepsia of an aggravated character.... [W]hen the attacks were on he seemed almost crushed with agony, the nervous system being severely shaken.... [O]f course, such attacks as I have spoken were only occasional-for no constitution could have borne up long under them in their acute phase."16 In all, 9 of 13 symptoms of panic disorder listed in the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) criteria were prominent in Darwin's illness.10

Darwin's illness also included agoraphobic features. In 1839, because of distress caused by being out in public, Darwin retreated from London to live "a life of extreme quietness."26 He said, "We [he and his wife Emma] have given up all parties, for they agree with neither of us."26Only infrequently did he leave the confines of his rural home in the hamlet of Down in Kent, and when he did so, he was usually accompanied by his wife. In a letter to Fox in 1872, he wrote: "How I wish I could accept your invitation and pay you a visit to Sandown; but I have long found it impossible to visit anywhere; the novelty and excitement would annihilate me."27 He also had an excessive fear of being alone. In 1848, while on a visit to his family in Shrewsbury, he described his emotional state in a letter to his wife: "Without you when sick I feel most desolate.... I do long to be with you and under your protection for then I feel safe."' These same feelings were expressed to Dr Chapman in 1865 as "nervousness when Emma leaves me."23

Its Natural History

The natural history of Darwin's illness is consistent with panic disorder. He, like many patients with this illness, had a premorbid vulnerability described as a sensitivity to stress or criticism in his youth 29 Although he had isolated symptoms earlier, his illness had its onset at the age of 28 years, which is typical for panic. Events, such as formulation of his evolutionary theory, which he feared would bring him into conflict with the British scientific establishment, may have contributed to the onset of his symptoms.24 Thereafter, his illness followed a chronic, fluctuating course but was complicated by hypochondriacal features, depressive episodes, and, as has been mentioned, agoraphobia.30

Typical of patients with panic disorder yet today, Darwin visited many physicians but failed to receive a definitive diagnosis or therapy.31 Nevertheless, panic disorder can be responsive to nonspecific factors so it is not surprising that his illness responded temporarily to the water cure, a new treatment consisting of baths and douches about which there was enthusiasm at the time 32 Darwin's illness waned in his later years. The declining prevalence of panic disorder with age that has been observed in community surveys may be due to amelioration of this kind, although other explanations exist.33

Panic Disorder

Darwin's illness bears a strong resemblance to panic disorder. Although ill for 45 years, Darwin remained free of physical or mental deterioration. In fact, his illness followed a waxing and waning course typical of the disorder. He had recurrent attacks that included palpitations, shortness of breath, nausea and abdominal distress, trembling, dizziness or lightheadedness, dying sensations, fear of losing control, and symptoms akin to depersonalization, and these were frequently triggered by phobic situations (eg, meetings, traveling, speaking before groups). His attacks caused him great distress and interfered with his work and social life. The clinical picture fits the criteria of DSM-IV and descriptions found in standard textbooks.10,34-36

In his writings Darwin also made reference to agoraphobic features that commonly accompany panic disorder. With the worsening of symptoms precipitated by travel and meetings, his activities became restricted. Before he became ill and during his studies at Cambridge (18271831), he traveled widely in England, Wales, and Scotland for geological surveys and biological collecting.4(pp56-59) Also, during the Beagle voyage (1831-1836), Darwin road horseback, climbed mountains, and weathered periodic natural disasters. However, within 2 years of the onset of his illness, he had begun to live "the life of a hermit."(P"5" Afterward, he had difficulty leaving his home at Down unless accompanied by his wife.

Patients with panic disorder experience somatic complaints that involve many organ systems and extend beyond the current criteria. In his classic description, Freud noted that "almost every accompanying symptom alone can constitute the attack just as well as anxiety itself."37 Darwin's symptoms adhere to Freud's insight. Prominent somatic symptoms included headache, tremulousness, palpitations, vomiting, and faintness. Although Darwin's illness may have had a functional gastrointestinal component (eg, functional nausea and vomiting, irritable bowel syndrome), prominent anxiety symptoms and avoidance of phobic situations point to a psychiatric disorder.' Variable intensity of symptoms and chronic, prolonged course without physical deterioration also indicate that his illness was psychiatric.39

Earlier Speculation

Earlier authors speculated on the nature of Darwin's malady, based on the same materials that we reviewed and reminiscences of persons who knew him. For example, obituaries written soon after his death postulated that his illness was the result of seasickness on the Beagle (1831-1836).40,41 Asa Gray,42 an American friend, observed that his illness was "not unlike seasickness" and others echoed this sentiment, including the author of an early biography.424 However, his symptoms were fluctuating with partial remissions lasting up to 18 months. Also, there is no evidence that seasickness can become chronic.150(p115)

Organic causes besides seasickness were also considered as explanations of Darwin's ill health. For example, Simpson44 suggested that Darwin may have suffered from chronic brucellosis, and subsequently Adler45 suggested Chagas disease, caused by the protozoon Trypanosoma cruzi. However, Woodruff46 expressed doubt that Darwin ever had Chagas disease, noting that no other member of the Beagle crew had symptoms of this condition and that infection with T cruzi occurs not from a bite but from contamination of a bite with excreta. In addition, Darwin experienced numerous partial exacerbations and remissions that would be unusual in the case of Chagas disease.

Other writers viewed Darwin's illness as mental or psychiatric in nature. For example, Johnston4 thought Darwin suffered from "chronic neurasthenia of a severe grade," and Keith4 postulated mental overwork. Neurasthenia, a term used in Johnston's day, implied nervous exhaustion arising from a loss of neural energy that, according to Beard,4" was common in modern civilizations. Beard4I") listed a wide variety of symptoms under this heading including insomnia, cerebral irritation, nervous dyspepsia, and fear of open and closed places. Anxiety neurosis and, more recently, panic disorder were separated from this earlier, more broadly defined category.10

In a letter to the British Medical Journal, Bowlby,51 a child psychologist, suggested that Darwin may have experienced hyperventilation. This diagnosis is in agreement with certain earlier writers who believed Darwin had suffered from Da Costa syndrome. Da Costa, a Union Army surgeon, described an affliction in Civil War soldiers that he termed "irritable heart."" His was an early description of what some now view as panic disorder. Bowlby noted that Darwin suffered from panic attacks and used a label, "hyperventilation syndrome," that is commonly applied to panic disorder by nonpsychiatric physicians. In his book, Charles Darwin: A New Life,l1) Bowlby went on to theorize about possible etiologic factors.

FINAL THOUGHTS

There are several limitations to our inquiry that may be difficult to resolve. A coexisting illness cannot be completely excluded. For example, Darwin may have taken arsenic (Fowler solution) from time to time as a treatment for intestinal symptoms, and some degree of arsenic poisoning cannot be ruled out.53However, several investigators have discredited this possibility.15(ppl32-139),54 Darwin self-administered nostrums for a variety of symptoms, and these may have contributed to his distress. For example, he maintained a "Receipts" book'S(ppI47-167) that contained medical prescriptions from his father to which he later made additions. There are a variety of organic illnesses, such as partial complex seizures or Meniere disease, that Darwin might conceivably have had. However, he never experienced olfactory or gustatory auras or stereotypic behavior typically associated with temporal lobe epilepsy.' Episodic vomiting may occur with Meniere disease, but Darwin did not report other symptoms associated with this disorder such as aural fullness, tinnitus, or hearing loss.56

Darwin's illness had an enormous impact on his life and work. It significantly changed his lifestyle from that of a worldwide collector and traveler to a recluse. However, as a consequence of his illness, he was able to narrow the focus of his energies. As he himself noted, "Even ill-health, though it has annihilated several years of my life, has saved me from the distraction of society and its amusements."4(p144) Had it not been for this illness, his theory of evolution might not have become the all-consuming passion that produced On the Origin of Species.

This Article has been submitted by the Jeremy's Prophecy Dot Com team for informational and educational purposes. Jeremy's Prophecy Dot Com is a website dedicated to telling the story of Jeremy Jacobs, a character in the novel, Jeremy's Prophecy Dot Com.