History of depression

Last updated

What was previously known as melancholia and is now known as clinical depression, major depression, or simply depression and commonly referred to as major depressive disorder by many health care professionals, has a long history, with similar conditions being described at least as far back as classical times.

Contents

Ancient to medieval period

The four temperaments clockwise from top left (sanguine; phlegmatic; melancholic; choleric) according to an ancient theory of mental states LavaterHollowayFaces.png
The four temperaments clockwise from top left (sanguine; phlegmatic; melancholic; choleric) according to an ancient theory of mental states

In ancient Greece, disease was thought due to an imbalance in the four basic bodily fluids, or humors . Personality types were similarly thought to be determined by the dominant humor in a particular person. Derived from the Ancient Greek melas, "black", and kholé, "bile", [1] melancholia was described as a distinct disease with particular mental and physical symptoms by Hippocrates in his Aphorisms, where he characterized all "fears and despondencies, if they last a long time" as being symptomatic of the ailment. [2]

Aretaeus of Cappadocia later noted that sufferers were "dull or stern; dejected or unreasonably torpid, without any manifest cause". The humoral theory fell out of favor but was revived in Rome by Galen. Melancholia was a far broader concept than today's depression; prominence was given to a clustering of the symptoms of sadness, dejection, and despondency, and often fear, anger, delusions and obsessions were included. [3]

Physicians in the Persian and then the Muslim world developed ideas about melancholia during the Islamic Golden Age. Ishaq ibn Imran (d. 908) combined the concepts of melancholia and phrenitis. [4] The 11th century Persian physician Avicenna described melancholia as a depressive type of mood disorder in which the person may become suspicious and develop certain types of phobias. [5]

His work, The Canon of Medicine , became the standard of medical thinking in Europe alongside those of Hippocrates and Galen. [6] Moral and spiritual observations also abounded, and in the Christian environment of medieval Europe, a malaise called acedia (sloth or absence of caring) was identified, involving a tendency of the will to low spirits and lethargy typically linked to isolation. [7] [8]

The seminal scholarly work of the 17th century was English scholar Robert Burton's book, The Anatomy of Melancholy , drawing on numerous theories and the author's own experiences. Burton suggested that melancholy could be combatted with a healthy diet, sufficient sleep, music, and "meaningful work", along with talking about the problem with a friend. [9] [10]

During the 18th century, the humoral theory of melancholia was increasingly being challenged by mechanical and electrical explanations; references to dark and gloomy states gave way to ideas of slowed circulation and depleted energy. [11] German physician Johann Christian Heinroth, however, argued melancholia was a disturbance of the soul due to moral conflict within the patient.

Eventually, various authors proposed up to 30 different sub-types of melancholia, and alternative terms were suggested and discarded. Hypochondria came to be seen as a separate disorder. Melancholia and melancholy had been used interchangeably until the 19th century, but the former came to refer to a pathological condition and the latter to a temperament. [3]

The term depression was derived from the Latin verb deprimere, "to press down". [12] From the 14th century, "to depress" meant to subjugate or to bring down in spirits. It was used in 1665 in English author Richard Baker's Chronicle to refer to someone having "a great depression of spirit", and by English author Samuel Johnson in a similar sense in 1753. [13] The term also came into use in physiology and economics.

An early usage referring to a psychiatric symptom was by French psychiatrist Louis Delasiauve in 1856, and by the 1860s it was appearing in medical dictionaries to refer to a physiological and metaphorical lowering of emotional function. [14] Since Aristotle, melancholia had been associated with men of learning and intellectual brilliance, a hazard of contemplation and creativity. The newer concept abandoned these associations and, through the 19th century, became more associated with women. [3]

Although melancholia remained the dominant diagnostic term, depression gained increasing currency in medical treatises and was a synonym by the end of the century; German psychiatrist Emil Kraepelin may have been the first to use it as the overarching term, referring to different kinds of melancholia as depressive states. [15] English psychiatrist Henry Maudsley proposed an overarching category of affective disorder. [16]

20th and 21st centuries

In the 20th century, the German psychiatrist Emil Kraepelin was the first to distinguish manic depression. The influential system put forward by Kraepelin unified nearly all types of mood disorder into manic–depressive insanity. Kraepelin worked from an assumption of underlying brain pathology, but also promoted a distinction between endogenous (internally caused) and exogenous (externally caused) types. [15]

The unitarian view became more popular in the United Kingdom, while the binary view held sway in the US, influenced by the work of Swiss psychiatrist Adolf Meyer and before him Sigmund Freud, the father of psychoanalysis. [17]

Sigmund Freud argued that depression, or melancholia, could result from loss and is more severe than mourning. Sigmund freud um 1905.jpg
Sigmund Freud argued that depression, or melancholia, could result from loss and is more severe than mourning.

Freud had likened the state of melancholia to mourning in his 1917 paper Mourning and Melancholia. He theorized that objective loss, such as the loss of a valued relationship through death or a romantic breakup, results in subjective loss as well; the depressed individual has identified with the object of affection through an unconscious, narcissistic process called the libidinal cathexis of the ego.

Such loss results in severe melancholic symptoms more profound than mourning; not only is the outside world viewed negatively, but the ego itself is compromised. [18] The patient's decline of self-perception is revealed in his belief of his own blame, inferiority, and unworthiness. [19] He also emphasized early life experiences as a predisposing factor. [3]

Meyer put forward a mixed social and biological framework emphasizing reactions in the context of an individual's life, and argued that the term depression should be used instead of melancholia. [16]

The DSM-I (1952) contained depressive reaction and the DSM-II (1968) depressive neurosis, defined as an excessive reaction to internal conflict or an identifiable event, and also included a depressive type of manic-depressive psychosis within Major affective disorders. [20]

In the mid-20th century, other psycho-dynamic theories were proposed. Existential and humanistic theories represented a forceful affirmation of individualism. [21] Austrian existential psychiatrist Viktor Frankl connected depression to feelings of futility and meaninglessness. [22] Frankl's logotherapy addressed the filling of an "existential vacuum" associated with such feelings, and may be particularly useful for depressed adolescents. [23] [24]

American existential psychologist Rollo May hypothesized that "depression is the inability to construct a future". [25] In general, May wrote that depression "occur[s] more in the dimension of time than in space," [26] and the depressed individual fails to look ahead in time properly. Thus the "focusing upon some point in time outside the depression ... gives the patient a perspective, a view on high so to speak; and this may well break the chains of the ... depression." [27]

Humanistic psychologists argued that depression resulted from an incongruity between society and the individual's innate drive to self-actualize, or to realize one's full potential. [28] [29] American humanistic psychologist Abraham Maslow theorized that depression is especially likely to arise when the world precludes a sense of "richness" or "totality" for the self-actualizer. [29]

Cognitive psychologists offered theories on depression in the mid-twentieth century. Starting in the 1950s, Albert Ellis argued that depression stemmed from irrational "should" and "musts" leading to inappropriate self-blame, self-pity, or other-pity in times of adversity. [30] Starting in the 1960s, Aaron Beck developed the theory that depression results from a "cognitive triad" of negative thinking patterns, or "schemas," about oneself, one's future, and the world. [31]

In the mid-20th century, researchers theorized that depression was caused by a chemical imbalance in neurotransmitters in the brain, a theory based on observations made in the 1950s of the effects of reserpine and isoniazid in altering monoamine neurotransmitter levels and affecting depressive symptoms. [32] During the 1960s and 70s, manic-depression came to refer to just one type of mood disorder (now most commonly known as bipolar disorder) which was distinguished from (unipolar) depression. The terms unipolar and bipolar had been coined by German psychiatrist Karl Kleist. [15]

The term major depressive disorder was introduced by a group of US clinicians in the mid-1970s as part of proposals for diagnostic criteria based on patterns of symptoms (called the Research Diagnostic Criteria, building on earlier Feighner Criteria), [33] and was incorporated into the DSM-III in 1980. [34] To maintain consistency the ICD-10 used the same criteria, with only minor alterations, but using the DSM diagnostic threshold to mark a mild depressive episode, adding higher threshold categories for moderate and severe episodes. [34] [35]

DSM-IV-TR excluded cases where the symptoms are a result of bereavement, although it was possible for normal bereavement to evolve into a depressive episode if the mood persisted and the characteristic features of a major depressive episode developed. [36] The criteria were criticized because they do not take into account any other aspects of the personal and social context in which depression can occur. [37] In addition, some studies found little empirical support for the DSM-IV cut-off criteria, indicating they are a diagnostic convention imposed on a continuum of depressive symptoms of varying severity and duration. [38]

The ancient idea of melancholia still survives in the notion of a melancholic sub-type. The new definitions of depression were widely accepted, albeit with some conflicting findings and views, and the nomenclature continues in DSM-IV-TR, published in 2000. [39]

There has been some criticism of the expansion of coverage of the diagnosis, related to the development and promotion of antidepressants and the biological model since the late 1950s. [40]

See also

Related Research Articles

Bipolar I disorder is a type of bipolar spectrum disorder characterized by the occurrence of at least one manic episode, with or without mixed or psychotic features. Most people also, at other times, have one or more depressive episodes. Typically, these manic episodes can last at least 7 days for most of each day to the extent that the individual may need medical attention, while the depressive episodes last at least 2 weeks.

<span class="mw-page-title-main">Major depressive disorder</span> Mood disorder

Major depressive disorder (MDD), also known as clinical depression, is a mental disorder characterized by at least two weeks of pervasive low mood, low self-esteem, and loss of interest or pleasure in normally enjoyable activities. Introduced by a group of US clinicians in the mid-1970s, the term was adopted by the American Psychiatric Association for this symptom cluster under mood disorders in the 1980 version of the Diagnostic and Statistical Manual of Mental Disorders (DSM-III), and has become widely used since. The disorder causes the second-most years lived with disability, after lower back pain.

<i>Diagnostic and Statistical Manual of Mental Disorders</i> American psychiatric classification

The Diagnostic and Statistical Manual of Mental Disorders is a publication by the American Psychiatric Association (APA) for the classification of mental disorders using a common language and standard criteria. It is the main book for the diagnosis and treatment of mental disorders in the United States and Australia, while in other countries it may be used in conjunction with other documents. The DSM-5 is considered one of the principal guides of psychiatry, along with the International Classification of Diseases (ICD), Chinese Classification of Mental Disorders (CCMD), and the Psychodynamic Diagnostic Manual. However, not all providers rely on the DSM-5 as a guide, since the ICD's mental disorder diagnoses are used around the world. Psychiatry like Medicine is not an exact science» and scientific studies often measure changes in symptom scale scores rather than changes in DSM-5 criteria to determine the real-world effects of mental health interventions.

<span class="mw-page-title-main">Dementia praecox</span> Obsolete medical term for the schizophrenia and autism spectrums

Dementia praecox is a disused psychiatric diagnosis that originally designated a chronic, deteriorating psychotic disorder characterized by rapid cognitive disintegration, usually beginning in the late teens or early adulthood. Over the years, the term dementia praecox was gradually replaced by the term schizophrenia, which initially had a meaning that included what is today considered the autism spectrum.

<span class="mw-page-title-main">Emil Kraepelin</span> German psychiatrist (1856–1926)

Emil Wilhelm Georg Magnus Kraepelin was a German psychiatrist. H. J. Eysenck's Encyclopedia of Psychology identifies him as the founder of modern scientific psychiatry, psychopharmacology and psychiatric genetics.

<span class="mw-page-title-main">Melancholia</span> Historical view of extreme depression

Melancholia or melancholy is a concept found throughout ancient, medieval, and premodern medicine in Europe that describes a condition characterized by markedly depressed mood, bodily complaints, and sometimes hallucinations and delusions.

<span class="mw-page-title-main">Mood disorder</span> Mental disorder affecting the mood of an individual, over a long period of time

A mood disorder, also known as an affective disorder, is any of a group of conditions of mental and behavioral disorder where a disturbance in the person's mood is the main underlying feature. The classification is in the Diagnostic and Statistical Manual of Mental Disorders (DSM) and International Classification of Diseases (ICD).

Schizoaffective disorder is a mental disorder characterized by abnormal thought processes and an unstable mood. This diagnosis requires symptoms of both schizophrenia (psychosis) and a mood disorder: either bipolar disorder or depression. The main criterion is the presence of psychotic symptoms for at least two weeks without any mood symptoms. Schizoaffective disorder can often be misdiagnosed when the correct diagnosis may be psychotic depression, bipolar I disorder, schizophreniform disorder, or schizophrenia. This is a problem as treatment and prognosis differ greatly for most of these diagnoses. Many people with schizoaffective disorder have other mental disorders including anxiety disorders.

<span class="mw-page-title-main">Depression (mood)</span> State of low mood and aversion to activity

Depression is a mental state of low mood and aversion to activity. It affects more than 280 million people of all ages. Depression affects a person's thoughts, behavior, feelings, and sense of well-being. Depressed people often experience loss of motivation or interest in, or reduced pleasure or joy from, experiences that would normally bring them pleasure or joy.

Depressive personality disorder is a psychiatric diagnosis that denotes a personality disorder with depressive features.

Cyclical variations in moods and energy levels have been recorded at least as far back as several thousand years. The words "melancholia" and "mania" have their etymologies in Ancient Greek. The word melancholia is derived from melas/μελας, meaning "black", and chole/χολη, meaning "bile" or "gall", indicative of the term's origins in pre-Hippocratic humoral theories. A man known as Aretaeus of Cappadocia has the first records of analyzing the symptoms of depression and mania in the 1st century of Greece. There is documentation that explains how bath salts were used to calm those with manic symptoms and also help those who are dealing with depression. Even today, lithium is used as a treatment to bipolar disorder which is significant because lithium could have been an ingredient in the Greek bath salt. Centuries passed and very little was studied or discovered. It wasn't until the mid-19th century that a French psychiatrist by the name of Jean-Pierre Falret wrote an article describing "circular insanity" and this is believed to be the first recorded diagnosis of bipolar disorder. Years later, in the early 1900s, Emil Kraepelin, a German psychiatrist, analyzed the influence of biology on mental disorders, including bipolar disorder. His studies are still used as the basis of classification of mental disorders today.

Involutional melancholia or involutional depression is a traditional name for a supposed psychiatric disorder which was thought to affect mainly elderly or late middle-aged people, often in association with paranoia.

The classification of mental disorders, also known as psychiatric nosology or psychiatric taxonomy, is central to the practice of psychiatry and other mental health professions.

<span class="mw-page-title-main">DSM-5</span> 2013 edition of the Diagnostic and Statistical Manual of Mental Disorders

The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), is the 2013 update to the Diagnostic and Statistical Manual of Mental Disorders, the taxonomic and diagnostic tool published by the American Psychiatric Association (APA). In 2022, a revised version (DSM-5-TR) was published. In the United States, the DSM serves as the principal authority for psychiatric diagnoses. Treatment recommendations, as well as payment by health care providers, are often determined by DSM classifications, so the appearance of a new version has practical importance. However, not all providers rely on the DSM-5 for planning treatment as the ICD's mental disorder diagnoses are used around the world and scientific studies often measure changes in symptom scale scores rather than changes in DSM-5 criteria to determine the real-world effects of mental health interventions. The DSM-5 is the only DSM to use an Arabic numeral instead of a Roman numeral in its title, as well as the only living document version of a DSM.

Bipolar II disorder (BP-II) is a mood disorder on the bipolar spectrum, characterized by at least one episode of hypomania and at least one episode of major depression. Diagnosis for BP-II requires that the individual must never have experienced a full manic episode. Otherwise, one manic episode meets the criteria for bipolar I disorder (BP-I).

<span class="mw-page-title-main">Recurrent brief depression</span> Type of depression

Recurrent brief depression (RBD) defines a mental disorder characterized by intermittent depressive episodes, not related to menstrual cycles in women, occurring between approximately 6–12 times per year, over at least one year or more fulfilling the diagnostic criteria for major depressive episodes except for duration in which RBD is less than 14 days. Despite the short duration of the depressive episodes, such episodes are severe, and suicidal ideation and impaired function is rather common. The majority of patients with RBD also report symptoms of anxiety and increased irritability. Hypersomnia is also rather frequent. About 1/2 of patients fulfilling diagnostic criteria for RBD may have additional short episodes of brief hypomania, which is a severity marker of RBD. RBD may be the only mental disorder present, however RBD may also occur as part of a history of recurrent major depressive episodes or bipolar disorders. RBD is also seen among some patients with personality disorders.

The word schizophrenia was coined by the Swiss psychiatrist Eugen Bleuler in 1908, and was intended to describe the separation of function between personality, thinking, memory, and perception. Bleuler introduced the term on 24 April 1908 in a lecture given at a psychiatric conference in Berlin and in a publication that same year. Bleuler later expanded his new disease concept into a monograph in 1911, which was finally translated into English in 1950.

Cyclothymia, also known as cyclothymic disorder, psychothemia / psychothymia, bipolar III, affective personality disorder and cyclothymic personality disorder, is a mental and behavioural disorder that involves numerous periods of symptoms of depression and periods of symptoms of elevated mood. These symptoms, however, are not sufficient to indicate a major depressive episode or a manic episode. Symptoms must last for more than one year in children and two years in adults.

<span class="mw-page-title-main">Melancholic depression</span> Medical condition

Melancholic depression, or depression with melancholic features, is a DSM-IV and DSM-5 specifier of depressive disorders. The specifier is used to distinguish clinically relevant subsets of causes and symptoms that have the potential to influence treatment.

<span class="mw-page-title-main">Kraepelinian dichotomy</span>

The Kraepelinian dichotomy is the division of the major endogenous psychoses into the disease concepts of dementia praecox, which was reformulated as schizophrenia by Eugen Bleuler by 1908, and manic-depressive psychosis, which has now been reconceived as bipolar disorder. This division was formally introduced in the sixth edition of Emil Kraepelin's psychiatric textbook Psychiatrie. Ein Lehrbuch für Studirende und Aerzte, published in 1899. It has been highly influential on modern psychiatric classification systems, the DSM and ICD, and is reflected in the taxonomic separation of schizophrenia from affective psychosis. However, there is also a diagnosis of schizoaffective disorder to cover cases that seem to show symptoms of both.

References

  1. Liddell, Henry; Scott, Robert (1980). A Greek-English Lexicon (Abridged ed.). UK: Oxford University Press. ISBN   0-19-910207-4.
  2. Hippocrates, Aphorisms, Section 6.23
  3. 1 2 3 4 Radden, J (March 2003). "Is this dame melancholy? Equating today's depression and past melancholia". Philosophy, Psychiatry, & Psychology. 10 (1): 37–52. doi:10.1353/ppp.2003.0081. S2CID   143684460.
  4. Jacquart, Danielle (1996). "The Influence of Arabic Medicine in the Medieval West". In Rashed, Roshdi (ed.). Encyclopedia of the History of Arabic Science: Technology, alchemy and life sciences. p. 980.
  5. Haque A (2004). "Psychology from Islamic perspective: Contributions of early Muslim scholars and challenges to contemporary Muslim psychologists". Journal of Religion and Health. 43 (4): 357–377 [366]. doi:10.1007/s10943-004-4302-z. S2CID   38740431.
  6. S Safavi-Abbasi, LBC Brasiliense, RK Workman (2007), The fate of medical knowledge and the neurosciences during the time of Genghis Khan and the Mongolian Empire, Neurosurgical Focus23 (1), E13, p. 3.
  7. Daly, RW (2007). "Before depression: The medieval vice of acedia". Psychiatry: Interpersonal and Biological Processes. 70 (1): 30–51. doi:10.1521/psyc.2007.70.1.30. PMID   17492910. S2CID   22080560.
  8. Merkel, L. (2003) The History of Psychiatry PGY II Lecture Archived 2010-12-23 at the Wayback Machine (PDF) Website of the University of Virginia Health System. Retrieved on 2008-08-04
  9. Kent 2003, p. 55.
  10. "The Anatomy of Melancholy by Robert Burton". Project Gutenberg. 1 April 2004. Retrieved 2008-10-19.
  11. Jackson SW (July 1983). "Melancholia and mechanical explanation in eighteenth-century medicine". Journal of the History of Medicine and Allied Sciences. 38 (3): 298–319. doi:10.1093/jhmas/38.3.298. PMID   6350428.
  12. "depress". Online Etymology Dictionary. Retrieved June 30, 2008.
  13. Wolpert, L. "Malignant Sadness: The Anatomy of Depression". The New York Times. Retrieved 2008-10-30.
  14. Berrios GE (September 1988). "Melancholia and depression during the 19th century: A conceptual history". British Journal of Psychiatry. 153 (3): 298–304. doi:10.1192/bjp.153.3.298. PMID   3074848. S2CID   145445990.
  15. 1 2 3 Davison, K (2006). "Historical aspects of mood disorders". Psychiatry. 5 (4): 115–18. doi:10.1383/psyt.2006.5.4.115.
  16. 1 2 Lewis, AJ (1934). "Melancholia: A historical review". Journal of Mental Science. 80 (328): 1–42. doi: 10.1192/bjp.80.328.1 .
  17. Parker, Hadzi-Pavlovic & Eyers 1996, p. 11.
  18. Carhart-Harris RL, Mayberg HS, Malizia AL, Nutt D (2008). "Mourning and melancholia revisited: Correspondences between principles of Freudian metapsychology and empirical findings in neuropsychiatry". Annals of General Psychiatry. 7 (1): 9. doi: 10.1186/1744-859X-7-9 . PMC   2515304 . PMID   18652673.
  19. Freud, S. (1984). "Mourning and Melancholia". In Richards, A. (ed.). 11.On Metapsychology: The Theory of Psycholoanalysis. Aylesbury, Bucks: Pelican. pp. 245–69. ISBN   0-14-021740-1.
  20. American Psychiatric Association (1968). "Schizophrenia" (PDF). Diagnostic and statistical manual of mental disorders: DSM-II. Washington, DC: American Psychiatric Publishing, Inc. pp. 36–37, 40. Archived from the original (PDF) on 2007-08-20. Retrieved 2008-08-03.
  21. A. Freeman; N. Epstein; KM Simon (1987), Depression in the family, New York: Haworth Press, pp. 64, 66
  22. Frankl VE (2000). Man's search for ultimate meaning. New York, NY, USA: Basic Books. pp. 139–40. ISBN   0-7382-0354-8.
  23. Seidner, Stanley S. (June 10, 2009) "A Trojan Horse: Logotherapeutic Transcendence and its Secular Implications for Theology". Mater Dei Institute. pp 14-15.
  24. Blair RG (October 2004). "Helping older adolescents search for meaning in depression". Journal of Mental Health Counseling. 26 (4): 333–347. doi:10.17744/mehc.26.4.w8u9h6uf5ybhapyl.
  25. Geppert CMA (May 2006). "Damage control". Psychiatric Times. Archived from the original on 2009-05-17. Retrieved 2008-11-08.
  26. May 1994 , p. 133
  27. May 1994 , p. 135
  28. Boeree, CG (1998). "Abraham Maslow: Personality Theories" (PDF). Psychology Department, Shippensburg University. Retrieved 2008-10-27.
  29. 1 2 Maslow A (1971). The Farther Reaches of Human Nature. New York, NY, USA: Viking Books. pp.  318. ISBN   0-670-30853-6.
  30. Ellis, Albert (1962). Reason and emotion in psychotherapy (Rev. and update. ed.). Secaucus, NJ: Carol Pub. Group. ISBN   1559722487.
  31. Beck, Aaron T. (1979). Cognitive therapy of depression (2nd ed.). New York: Guilford Press. ISBN   0-89862-000-7.
  32. Schildkraut, JJ (1965). "The catecholamine hypothesis of affective disorders: A review of supporting evidence". American Journal of Psychiatry. 122 (5): 509–22. doi:10.1176/ajp.122.5.509. PMID   5319766.
  33. Spitzer RL, Endicott J, Robins E (1975). "The development of diagnostic criteria in psychiatry" (PDF). Archived from the original (PDF) on 2005-12-14. Retrieved 2008-11-08.
  34. 1 2 Philipp M, Maier W, Delmo CD (1991). "The concept of major depression. I. Descriptive comparison of six competing operational definitions including ICD-10 and DSM-III-R". European Archives of Psychiatry and Clinical Neuroscience. 240 (4–5): 258–65. doi:10.1007/BF02189537. PMID   1829000. S2CID   36768744.
  35. Gruenberg, A.M., Goldstein, R.D., Pincus, H.A. (2005) Classification of Depression: Research and Diagnostic Criteria: DSM-IV and ICD-10 (PDF). Wiley.com. Retrieved on October 30, 2008.
  36. American Psychiatric Association 2000a , p. 352
  37. Wakefield JC, Schmitz MF, First MB, Horwitz AV (April 2007). "Extending the bereavement exclusion for major depression to other losses: evidence from the National Comorbidity Survey". Archives of General Psychiatry. 64 (4): 433–40. doi: 10.1001/archpsyc.64.4.433 . PMID   17404120.
  38. Kendler KS, Gardner CO (February 1998). "Boundaries of major depression: an evaluation of DSM-IV criteria". The American Journal of Psychiatry. 155 (2): 172–77. doi:10.1176/ajp.155.2.172. PMID   9464194. S2CID   8102276.
  39. American Psychiatric Association 2000a , p. 345
  40. Healy, David (1999). The Antidepressant Era. Cambridge, MA: Harvard University Press. p. 42. ISBN   0-674-03958-0.

Cited texts