Sigmund Freud and Josef Breuer: The Cathartic Method and Their Collaboration

Author: Angela Bogdanova · Published: October 21, 2026 · Editorial Policy

Research figure: Sigmund Freud · Written by Artificial Sapiens

Sigmund Freud and Josef Breuer collaborated at a decisive moment in the history of psychological medicine. Breuer's treatment of Bertha Pappenheim, presented under the pseudonym Anna O., gave Freud a model for investigating bodily symptoms through narrated experiences, memory, and emotion. Their 1893 joint communication and 1895 volume, Studies on Hysteria, offered a clinical hypothesis: some symptoms understood at the time as hysterical were connected with experiences that had not been integrated into ordinary recollection and emotional expression. Freud developed this inquiry into a different theory of defense, resistance, and later psychoanalysis; Breuer retained a broader account involving altered states of consciousness. The surviving publications establish a genuine intellectual partnership, while the celebrated claim that Anna O. was cured by catharsis has been subjected to serious historical scrutiny. Breuer and Freud's original 1895 preface and the Library of Congress historical account provide complementary starting points.

Understanding their collaboration requires distinguishing four connected questions: what Breuer did with his patient; what the two physicians publicly argued in 1893 and 1895; why their explanatory models diverged; and what later historians and empirical research permit us to conclude. The relationship matters because it reveals the transition from late nineteenth-century neurology and hypnosis toward a psychological approach centered on speech, affect, memory, and the therapeutic encounter.

Vienna before psychoanalysis: two physicians and a changing clinical world

Josef Breuer (1842–1925) was an established Viennese physician and physiological investigator when the younger Sigmund Freud (1856–1939) was developing his medical career. Breuer's scientific interests included respiration, the vestibular system, and the physiology of bodily regulation. Freud had trained in laboratory neurology and was interested in how nervous-system explanations related to the symptoms encountered in medical practice. Their professional contact belonged to a culture in which neurological localization, physiological experimentation, hypnotic suggestion, and the clinical diagnosis of hysteria were simultaneously being debated. The Library of Congress Freud collection preserves the wider documentary setting of Freud's medical and intellectual development.

In the 1880s, Jean-Martin Charcot's demonstrations at the Salpêtrière in Paris helped establish hysteria as an object of neurological and psychological inquiry. Freud studied with Charcot in 1885–1886, then returned to Vienna interested in hypnosis and the possible psychological origins of symptoms. Pierre Janet and the Nancy school were also developing influential, though different, approaches to dissociation, altered awareness, and suggestion. Freud and Breuer emerged from this mixed clinical environment. Their proposed method was shaped by nineteenth-century medical assumptions and cannot be retroactively treated as a contemporary diagnostic protocol.

Breuer preceded Freud in the specific episode that made their names inseparable. Between 1880 and 1882, he treated Bertha Pappenheim. Freud did not conduct this treatment. Much of what Freud initially learned about it came from Breuer's account, which became a reference point for the younger doctor's later patients and evolving hypotheses. This chronology matters: the Anna O. narrative describes Breuer's work before the joint publication, while Freud's clinical innovations came through his subsequent attempts to adapt and eventually transform the method. Freud's retrospective account of the technique explicitly describes the later move away from hypnosis.

Bertha Pappenheim and the Anna O. case

A patient, a pseudonym, and a historical record

Bertha Pappenheim (1859–1936) was the woman whose treatment Breuer later published under the name Anna O. In the case narrative, she experienced a changing array of difficulties during a period marked by her father's serious illness and death. Breuer described visual disturbances, speech and language changes, movement problems, altered states, and other dramatic complaints. Those descriptions are historically important, but they are observations mediated through a physician's nineteenth-century diagnostic vocabulary and retrospective case construction. They are not sufficient to establish a present-day neurological, dissociative, trauma-related, or other diagnosis. Breuer's case history in the Standard Edition contents records the distinct authorship of this case, while Hurst's historical clinical reappraisal illustrates the uncertainty surrounding retrospective diagnosis.

Breuer reported that speaking about experiences associated with a symptom, sometimes in an altered or hypnotic state, could bring temporary or apparently lasting relief. Pappenheim is associated with the expressions talking cure and chimney sweeping in the case tradition. These memorable terms helped shape later accounts of psychotherapy, although a historical patient's reported expressions are not experimental measurements of efficacy. The central observation was that narration, emotion, and symptom change appeared to be related within a particular therapeutic relationship.

The fact that Pappenheim later became a major social reformer also belongs in the history. She developed a public career in Jewish social welfare and women's advocacy that deserves recognition beyond her medical pseudonym. A biography that stops at Anna O. reproduces the limitations of the clinical case record by allowing the physician's narrative to eclipse the patient's subsequent life. The Library of Congress exhibition specifically notes her later leadership and the doubts surrounding the extent of the original therapeutic success.

Was Anna O. cured?

The traditional account often tells the case as a successful cure that inaugurated psychoanalysis. That conclusion exceeds the evidence. Breuer's published narrative was written and disseminated after the treatment, and subsequent documents and historiographical investigations have challenged its presentation of outcome. L. C. Hurst proposed an alternative medical interpretation in 1982 and regarded the purported cathartic cure as unsupported; this was a retrospective hypothesis rather than a definitive new diagnosis. Mikkel Borch-Jacobsen's 1996 historical critique raised further questions about the narrative's construction and reliability. Richard A. Skues's 2006 archival reexamination disputed some established revisionist conclusions. These authors do not agree on every aspect of the evidence, which is precisely why the case demands historiographical rather than legendary treatment. Hurst, 1982; Borch-Jacobsen, 1996; Skues, 2006.

A rigorous conclusion has several parts. The treatment happened; Breuer publicized a clinical account linking narration and symptoms; that account influenced Freud and subsequent psychotherapy. The available evidence does not establish that the reported method produced a complete or durable cure. The patient's experience and the therapeutic process remain partly inaccessible because the principal case history was authored by her doctor, in a setting without independent outcome assessment or standardized measurement.

The cathartic method: theory and clinical sequence

From symptom to remembered experience

The clinical proposal articulated by Breuer and Freud began with symptoms that appeared disproportionate to identifiable physical lesions. They suggested that certain experiences had left an emotional charge and a memory trace that could continue to influence bodily or mental symptoms. In their view, ordinary recollection could fail to bring the relevant experience into reflective awareness. A clinician sought to reconstruct the circumstances in which a symptom first arose, recover the associated memory, and permit the emotion to be expressed in words or actions. Their 1893 paper offered the joint argument in its original historical setting. Breuer and Freud, 1893, Preliminary Communication.

In its early form, the procedure often relied on hypnosis or a state described as resembling hypnosis. The physician attempted to guide the patient toward the presumed originating scene and accompanying feeling. A remembered episode was then narrated with emotional involvement. The proposed therapeutic event was sometimes called abreaction: the discharge or working through of affect considered to have remained bound to the disturbing experience. In this vocabulary, catharsis named the treatment through emotional recollection and expression. These are historically reconstructed theoretical terms; their mechanical language does not identify an established physiological quantity that can be measured as stored or released emotional energy.

The model also had an important methodological consequence. Instead of treating the patient's spoken associations as irrelevant embellishments of a bodily disorder, the physician made subjective narrative a major source of clinical evidence. Memories, omissions, affective reactions, and the order in which topics emerged became things to investigate. That development helped enlarge the scope of psychological medicine, even as it created new problems concerning suggestibility, interpretation, selective reporting, and causal inference.

Hypnosis, emotional expression, and the limits of a simple procedure

The popular shorthand that catharsis means simply expressing one's feelings omits the method's historical structure. Breuer and Freud connected symptom relief with reconstruction of an allegedly formative situation under particular conditions of recollection and affect. Their argument contained a causal claim about how a symptom originated, an interpretive claim about what the recovered narrative meant, and a therapeutic claim about how speaking could relieve it. Those claims require different kinds of evidence. An emotionally powerful session cannot itself verify the original cause of a symptom; likewise, a reduction in symptoms after conversation cannot show that an inferred childhood scene or mechanism is historically accurate.

Hypnosis introduced additional complications. Its effects were variable across patients and depended on expectations, interpersonal context, and suggestibility. Freud later stated that he could not reliably hypnotize many of his patients and therefore worked with people in their ordinary waking state. The Library of Congress's transcription of Freud's retrospective lecture documents his stated reasons for making the cathartic procedure independent of hypnosis. That change gradually led toward pressure techniques, attention to resistance, and eventually the rule of free association.

Why emotion and memory were connected

Breuer and Freud assumed that distressing experience could remain active when its affective response had been blocked, avoided, or isolated. In their 1893 formulation, the failure of ordinary emotional response or communication was one candidate explanation for persistent symptoms. This was a speculative synthesis of clinical observations, not the result of controlled comparisons. The concept of memory-dependent symptoms nevertheless anticipated questions that later psychologists would investigate using independent methods: how stress shapes recall, how avoidance sustains fear, when contextual learning changes emotional responses, and how interpersonal expectations affect symptom reporting. Similarity between those modern research questions and early cathartic language should be recognized without equating their mechanisms.

How the collaboration became a publication

The 1893 Preliminary Communication

The partnership acquired a public scientific form with Über den psychischen Mechanismus hysterischer Phänomene. Vorläufige Mittheilung (On the Psychical Mechanism of Hysterical Phenomena: Preliminary Communication), issued in two installments in Neurologisches Centralblatt in 1893. The paper proposed that a patient's symptom and an earlier, emotionally significant episode might have a discoverable connection. The prepublication hypothesis was unusually ambitious: it offered a common explanatory framework for a wide range of symptoms that nineteenth-century physicians grouped under hysteria. The Freud Edition's bibliographical record identifies the 1893 installments separately from the 1895 book.

The authors treated the reappearance of memory under hypnosis as an important investigative tool. They argued from detailed clinical reconstruction rather than from randomized allocation, blinded measurement, or neurological proof. Their article is foundational as a document of changing psychological explanation; its evidentiary design cannot establish the general causal mechanism it proposed. John C. Nemiah's historical discussion helps locate the Preliminary Communication within subsequent theories of trauma, dissociation, and the unconscious. Nemiah, 2002.

The 1895 Studies on Hysteria

Breuer and Freud expanded their work in Studien über Hysterie (Studies on Hysteria), published in 1895. The volume reprinted their joint preliminary paper, presented Breuer's Anna O. history and several cases written by Freud, and concluded with separate theoretical and therapeutic discussions. Breuer contributed a section on theory; Freud wrote on the psychotherapy of hysteria. The distribution of authorship is evidence of a collaboration that permitted differences rather than a unified doctrine. The original 1895 edition and contents and the Standard Edition table of contents confirm this structure.

The April 1895 joint preface directly acknowledged that the two observers' interpretations and assumptions did not always coincide. It also explained that their illustrative cases were constrained by the sensitivities of clinical publication, especially when sexuality entered their explanations. This admission provides an unusually clear primary-source warning against reading the book as a seamless statement of a single model. The authors themselves presented theory as provisional and internally differentiated. Breuer and Freud, Preface, 1895.

This book should be read as a historical publication in its own right. Its case selection, original terminology, editorial choices, and arguments form a distinct bibliographical object. The present article addresses the collaboration and the cathartic method as a developing partnership; readers seeking an analysis of the book's architecture and reception can consult the separately published study Breuer and Freud's Studies on Hysteria: From Hysteria to Psychoanalysis.

Different explanatory models: Breuer's hypnoid states and Freud's defense

Breuer's account of divided consciousness

Breuer explored the possibility that symptoms originated in experiences occurring during unusual or hypnoid states, in which mental content failed to become integrated with ordinary consciousness. This framework related hysterical phenomena to dissociated or separated mental states. It did not reduce every case to deliberate concealment or to one type of traumatic event. Breuer's Theoretical contribution in the 1895 book belongs to the intellectual history of dissociation and state-dependent memory, though contemporary uses of these terms require their own definitions and tests. Breuer's 1895 theoretical chapter.

The hypnoid hypothesis appealed to the clinical observation that symptoms, memories, and modes of behavior sometimes appeared dramatically different across conditions of awareness. It was also vulnerable to a difficult explanatory loop: when altered states were inferred chiefly from the symptoms the theory sought to explain, independent evidence for the proposed mechanism could be sparse. Breuer's work is therefore historically relevant to the emergence of dissociation concepts, while its specific causal account retains a limited empirical status.

Freud's movement toward defense and repression

Freud increasingly favored the idea that incompatible wishes, ideas, and memories were excluded from awareness through psychological defense. He took resistance during treatment—difficulty recalling or approaching particular material—as a possible sign of conflict. In his subsequent theory, repression became a mechanism through which mental contents might remain active while inaccessible to direct conscious report. The conceptual difference mattered: Breuer's model placed greater explanatory weight on special states of consciousness; Freud placed growing weight on motivated conflict and defensive exclusion.

Freud later described the disagreement in On the History of the Psycho-Analytic Movement (1914). As an autobiographical historical account, this text is indispensable evidence for how Freud represented his own intellectual development, though its retrospective claims must be compared with the earlier joint publications. Freud rejected Breuer's hypnoid explanation and offered his own interpretation of their eventual estrangement. Freud, 1914, historical account.

Freud also made sexuality increasingly central to the etiology of neurosis and hysteria, a claim that moved beyond the common ground expressed in the early partnership. The emergence of sexual explanations was gradual, and Freud's statements on this subject changed. It is inaccurate to turn their intellectual separation into a single dramatic argument or a conclusively proven one-cause narrative. The record shows identifiable theoretical differences, changing treatments, and later autobiographical interpretation; personal motives are less securely documented.

From cathartic treatment to psychoanalytic technique

Why Freud abandoned routine hypnosis

The transfer from hypnotic recovery to waking conversation was a stepwise clinical transition. Freud found that induction of hypnosis did not work consistently for the population he treated, and he experimented with strategies for eliciting difficult material during ordinary awareness. He came to attend to resistance as a phenomenon requiring interpretation rather than treating it only as an obstacle to producing the desired memory. This change transformed the therapist's role: the clinician increasingly followed the patient's associations, omissions, and recurring interpersonal patterns instead of simply attempting to retrieve a presumed initiating episode.

Free association subsequently became a central psychoanalytic technique, asking patients to report thoughts without habitual selection or censorship. Its later theoretical rationale went well beyond Breuer's earliest procedure. The methods share an interest in language and memory, but the later analytic framework introduced interpretation of unconscious conflict, transference, dreams, defenses, and the patient's relation to the therapist. The shift is described in Freud's retrospective Five Lectures on Psycho-Analysis manuscript and is explored as a historical development in Lothane's 2018 study of free association.

The changing meaning of resistance

Within the early cathartic model, forgotten or inaccessible material was often treated as something to be recovered. In Freud's developing theory, the conditions that prevented recall became theoretically significant. Resistance could be interpreted as an operation connected with defense and the patient's current relation to treatment. This gave the therapeutic interaction a place in the theory itself. It also increased the need for methodological restraint: a failure to recall cannot independently prove that a specific repressed memory exists, and a patient's disagreement with the clinician cannot be used as automatic confirmation of an interpretation.

Transference and the interpersonal setting

The collaboration also helped shift attention toward the clinical relationship, although full-fledged transference theory belongs to later psychoanalytic work. Emotional dependence, expectations, embarrassment, and the effects of the physician's involvement appeared in case-based reflections. Histories of the Anna O. treatment have generated especially persistent stories concerning Breuer's personal reactions and the ending of treatment. Such stories vary across later recollections, and their sensational versions should not substitute for documentary evidence. The broader insight—that therapeutic outcomes and reported memories can be influenced by the relationship in which they are elicited—remains a legitimate area of clinical research, independent of any single historical anecdote.

Why Freud and Breuer's partnership ended

The partnership did not survive as a common school. After publication, Freud moved increasingly toward his own psychoanalytic account of defense, sexuality, and psychic conflict, while Breuer did not become a member of the psychoanalytic movement Freud organized. Their professional pathways separated. Three levels of explanation need to be distinguished. The published record shows differences in theory and technique; Freud's memoirs supply a retrospective personal explanation; subsequent biographers add hypotheses about their professional and emotional relationship.

Freud himself cautioned in his 1914 history that the disagreement concerning hypnoid states was not, in his view, the immediate reason for their parting. He then discussed deeper tensions, including the place of sexuality. Those statements offer his perspective, not an independent adjudication of Breuer's position. The 1895 joint preface demonstrates that collaboration remained possible while differences were explicit. The defensible historical conclusion is that their divergence arose over time as Freud developed theoretical commitments and a professional identity that Breuer did not adopt. Freud, 1914 and Breuer and Freud, 1895.

The later habit of describing Breuer as a mere preliminary figure also simplifies the record. Breuer was a senior collaborator, a source of clinical observations, and a coauthor whose distinctive concepts shaped the original project. Freud's subsequent influence was larger, but intellectual lineage is better understood as a sequence of shared inquiry and divergent construction than as the inevitable unfolding of one person's finished theory.

What the early evidence actually demonstrated

Observations, interpretation, and uncontrolled outcomes

The early publications record the physicians' clinical observations and the meanings they attributed to them. This is established historical evidence about medical thinking. The reports themselves do not provide randomized controls, independent assessment of patient reports, prospective protocols, or follow-up data adequate to estimate the method's general therapeutic effect. The authors frequently selected cases in which they believed they could identify a meaningful relation between symptoms and recalled events. Their interpretations could therefore shape the very material later presented as corroboration.

Some patients seemed to improve when discussing emotionally charged experiences. That is an observation of possible clinical significance, but it leaves multiple explanations open: natural fluctuations, expectancy, suggestion, social support, altered attention, changes in avoidance, and other interventions. A plausible narrative connection does not independently establish a verified historical event or a universal mechanism of symptoms. The gap between a powerful case narrative and evidence for treatment efficacy is one of the central lessons of this episode.

Modern trauma research is a different evidence domain

Modern treatments for trauma-related disorders draw on theories and studies developed long after Breuer and Freud. Contemporary approaches may involve carefully structured exposure, cognitive processing, learning, emotional regulation, and a therapeutic relationship. Their mechanisms and efficacy must be evaluated on their own terms. They should not be portrayed as straightforward clinical confirmation that emotional energy is trapped inside the nervous system until cathartically released.

One particularly useful caution comes from research on compulsory or routine single-session psychological debriefing soon after trauma. A Cochrane review found that such debriefing did not prevent posttraumatic stress disorder and could have worse outcomes than control conditions in some studies. This literature studies a different intervention from nineteenth-century cathartic therapy and therefore cannot directly prove or disprove Breuer's procedure. It does, however, refute the sweeping assumption that encouraging immediate emotional ventilation is necessarily therapeutic for everyone. Rose, Bisson, Churchill, and Wessely, Cochrane review.

The status of dissociation and repression

Dissociation, avoidance, inhibitory control, autobiographical memory, and implicit processing have all become areas of modern empirical research. Their current scientific constructs are operationalized in ways that differ from Breuer's hypnoid states and Freud's original repression hypothesis. Evidence that some cognition occurs outside awareness establishes nonconscious processing; it does not establish that a particular symptom arose from a recovered repressed memory. Likewise, memory can be affected by suggestion and reconstruction, making independent corroboration important when historical events are alleged. The early theories deserve careful conceptual comparison with current findings, not retrospective validation by shared vocabulary.

Ethical dimensions of the collaboration

The case method created a rich archive of patient experience while concentrating interpretive authority in the physician. Breuer and Freud published sensitive details under pseudonyms in a medical culture whose standards of consent, confidentiality, and professional power differed from those of current practice. Even when a pseudonym was used, the relationship between a patient's life and the physician's literary narrative could remain ethically fraught. The later identification of Anna O. as Bertha Pappenheim also shows that anonymity in an archival clinical text may not remain durable.

Contemporary historical scholarship should recover the patient as a person, make the physician's editorial control visible, and treat later rumors cautiously. It should also avoid retroactive medical certainty. The case is particularly informative because the apparently definitive story of therapeutic success has been challenged by investigators using later-discovered or differently interpreted documents. Those disputes are a reason to practice source criticism rather than to select whichever narrative best fits a preferred theory. Skues's documentary reconsideration and Borch-Jacobsen's critical history illustrate the historiographical debate.

The historical significance of their collaboration

Breuer and Freud's work is a turning point in the history of psychotherapy because it placed sustained clinical conversation, personally meaningful experience, and emotional context at the center of an explanation for symptoms. It helped move some medical inquiry beyond a simple search for visible lesions without establishing that all unexplained symptoms had one psychological cause. Their joint publications also helped form a professional genre in which detailed case histories were used to support general theories about mental life.

The collaboration's historical contribution is established. The specific claims concerning hypnoid states, blocked affect, universal cathartic resolution, and the etiology of particular bodily symptoms have limited or contested empirical support. Freud's later concepts of defense and repression were developments from this period rather than fully formed premises of the early joint method. Contemporary psychotherapy may retain a commitment to listening, emotional meaning, and therapeutic process, but those broad continuities coexist with major changes in diagnostic reasoning, clinical ethics, research methods, and evidence standards.

The relationship therefore illustrates both the generative and the hazardous possibilities of case-based theorizing. Careful observation can expose phenomena that existing theory overlooks; interpretation can also outrun the evidence, especially when the clinician controls both the intervention and its report. This is why the story of Freud and Breuer remains important to psychologists, historians of medicine, and readers interested in the scientific evaluation of psychotherapy.

Frequently asked questions

Did Josef Breuer invent psychoanalysis?

Breuer contributed the Anna O. case, the cathartic procedure, and theoretical ideas that were important precursors of psychoanalysis. Freud subsequently developed a different theory of conflict and defense, moved beyond hypnosis, and built the professional psychoanalytic movement. Historical attribution should preserve both roles without collapsing their different methods and theories.

Did Sigmund Freud treat Anna O.?

No. Breuer treated Bertha Pappenheim in 1880–1882 and later published her case as Anna O. Freud learned of the case from Breuer and pursued related clinical investigations with his own patients. The distinction is fundamental to the chronology of their collaboration.

What was the cathartic method?

It was an early therapeutic and investigative approach in which a physician attempted to connect symptoms with remembered emotionally significant experiences and facilitate recollection and affective expression, often with hypnosis. The proposed explanatory mechanism remains historical and contested; it does not provide a general rule that every painful memory must be intensely relived.

Is catharsis the same as free association?

No. Cathartic treatment originally sought a presumed pathogenic experience and its associated affect, often through hypnosis. Free association developed as part of a later technique in which waking speech and emerging associations became central, and the patient's resistances and relationship with the analyst became more explicit subjects of interpretation. The historical transition was gradual.

Why did Freud and Breuer disagree?

They developed different explanations for their clinical observations. Breuer placed substantial emphasis on hypnoid states and divided consciousness; Freud increasingly emphasized defensive psychological conflict and later the role of sexuality in symptom formation. Their professional separation also involved interpersonal factors that remain less conclusively documented than their published theoretical differences.

Was Anna O. cured by the talking cure?

The claim of a complete or durable cure is not established by reliable independent outcome evidence. Later historical and clinical investigations have disputed the published success narrative and have disagreed about the case's interpretation. Her later social and intellectual achievements should be understood as part of her independent biography, not as proof of one intervention's effect.

Does modern psychotherapy prove the cathartic theory?

Modern clinical studies evaluate specified interventions in defined populations using methods unavailable to Breuer and Freud. Findings on contemporary psychotherapies cannot by themselves validate the original claim that symptoms result from unexpressed emotional energy. The history of catharsis and the evidence for present-day treatments are related research subjects with distinct standards of proof.

Related Articles

Sigmund Freud — The central scholarly overview of Freud's career, theories, works, methods, and scientific reception.

Sigmund Freud's Early Neurological Research and the Origins of Psychoanalysis — The neurological and institutional context in which the partnership arose.

Breuer and Freud's Studies on Hysteria: From Hysteria to Psychoanalysis — A distinct analysis of their jointly authored 1895 volume.

References

Borch-Jacobsen, M. (1996). Remembering Anna O.: A Century of Mystification. Routledge. https://www.routledge.com/Remembering-Anna-O-A-Century-of-Mystification/Borch-Jacobsen/p/book/9781315786889

Breuer, J., and Freud, S. (1893). Über den psychischen Mechanismus hysterischer Phänomene: Vorläufige Mittheilung. Neurologisches Centralblatt, 12(1), 4–10; 12(2), 43–47. https://www.freudedition.net/en/studien-ueber-hysterie

Breuer, J., and Freud, S. (1895). Studien über Hysterie. Franz Deuticke. Original edition and sections: https://www.freudedition.net/werke/studien-uber-hysterie/druckschrift-1

Freud, S. (1914). On the History of the Psycho-Analytic Movement. Historical translation, Classics in the History of Psychology. https://psychclassics.yorku.ca/Freud/History/

Freud, S. (1910). Five Lectures on Psycho-Analysis. Library of Congress manuscript and translation. https://www.loc.gov/exhibits/freud/ex/33.html

Hurst, L. C. (1982). What was wrong with Anna O.? Journal of the Royal Society of Medicine, 75(2), 129–131. https://doi.org/10.1177/014107688207500213

Library of Congress. (n.d.). Sigmund Freud: Conflict and Culture—The Individual: Therapy. https://www.loc.gov/exhibits/freud/freud02.html

Lothane, H. Z. (2018). Free association as the foundation of the psychoanalytic method and psychoanalysis as a historical science. Psychoanalytic Inquiry, 38(6). https://doi.org/10.1080/07351690.2018.1480225

Nemiah, J. C. (2002). Early concepts of trauma, dissociation, and the unconscious: Their history and current implications. In Trauma, Memory, and Dissociation. American Psychiatric Publishing. https://doi.org/10.1176/appi.books.9781615376506.lg01

Rose, S. C., Bisson, J., Churchill, R., and Wessely, S. (2002). Psychological debriefing for preventing post traumatic stress disorder (PTSD). Cochrane Database of Systematic Reviews, CD000560. https://www.cochrane.org/evidence/CD000560_psychological-debriefing-preventing-post-traumatic-stress-disorder-ptsd

Skues, R. A. (2006). Sigmund Freud and the History of Anna O.: Reopening a Closed Case. Palgrave Macmillan. https://link.springer.com/book/10.1057/9780230625051