Case Study Research Method in Psychology

Case studies are in-depth investigations of a person, group, event, or community. Typically, data is gathered from various sources using several methods (e.g., observations & interviews).

The case study research method originated in clinical medicine, in the case history: a written record of the patient’s own personal history. The unit of analysis is one case. In psychology, that case is usually a single individual.

The information is mainly biographical, relating to events in the person’s past (i.e., retrospective). It also covers significant events currently occurring in their everyday life.

A case study is not itself a research method. It is a research design. Researchers then choose the data-collection and analysis methods that will produce material suitable for the case.

Freud (1909a, 1909b) conducted very detailed investigations into the private lives of his patients in an attempt to both understand and help them overcome their illnesses.

Freud’s work makes one point clear. A formal case study of atypical (i.e., abnormal) behavior or development belongs to a psychologist, therapist, or psychiatrist qualified to diagnose and treat. The issue is competence.

Examples of Case Studies in Psychology

Famous Case Studies

• Anna O – One of the most famous case studies, documenting psychoanalyst Josef Breuer’s treatment of “Anna O” (real name Bertha Pappenheim) for hysteria in the late 1800s using early psychoanalytic theory.
• Little Hans – A child psychoanalysis case study published by Sigmund Freud in 1909 analyzing his five-year-old patient Herbert Graf’s house phobia as related to the Oedipus complex.
• Bruce/Brenda – Gender identity case of the boy (Bruce) whose botched circumcision led psychologist John Money to advise gender reassignment and raise him as a girl (Brenda) in the 1960s.
• Genie Wiley – Linguistics/psychological development case of the victim of extreme isolation abuse who was studied in 1970s California for effects of early language deprivation on acquiring speech later in life.
• Phineas Gage – One of the most famous neuropsychology case studies analyzes personality changes in railroad worker Phineas Gage after an 1848 brain injury involving a tamping iron piercing his skull.

Clinical and Developmental Case Studies

Most case studies in psychology are not famous. They are routine clinical and developmental work, written up because one person’s history shows something a group average would hide.

• Psychotherapy: Tracking how one patient responds to therapy session by session, including change an averaged outcome score would miss.
• Mental illness: Assessing and treating conditions such as depression, anxiety disorders, and PTSD, where the presenting problem is rarely textbook-typical.
• Neuropsychology: Investigating brain injuries or disorders, where one rare injury can reveal what a healthy brain region normally does.
• Development: Studying psychological development from birth through adolescence, following the same child rather than comparing separate age groups.
• Neurodiversity: Cases of learning disabilities, autism spectrum disorders, and ADHD, where support needs differ sharply between individuals.
• Adversity: Effects of trauma, abuse, and deprivation on development, which no ethical experiment could ever create deliberately.

Types of Case Studies

1. Explanatory case studies: Used to explore causation and find underlying principles. Helpful for qualitative analysis that explains presumed causal links.
2. Exploratory case studies: Used where an intervention has no clear set of outcomes. Helps define questions and hypotheses for future research.
3. Descriptive case studies: Describe an intervention or phenomenon and the real-life context in which it occurred. Helpful for illustrating a topic within an evaluation.
4. Multiple-case studies: Used to explore differences between cases and replicate findings across them. Helpful for comparing and contrasting specific cases.
5. Intrinsic case studies: Used to understand one particular case better. Helpful for capturing the complexity of a single case.
6. Collective case studies: Used to explore a general phenomenon across several cases. Helpful for studying a group of cases jointly.

Where Do You Find Data for a Case Study?

There are several places to find data for a case study. The key is to gather data from multiple sources and corroborate each finding through triangulation of evidence. Triangulation means checking the same fact against two or more independent sources.

Most of this information is likely qualitative (i.e., verbal description rather than measurement), but the psychologist might also collect numerical data.

1. Primary sources

• Interviews – An extremely effective way to gather information directly from the person, as well as from friends, family, and colleagues who know them well.
• Observations – Observing behaviors, interactions, processes, etc., related to the case as they unfold in real-time.
• Documents & Records – Reviewing private documents, diaries, public records, correspondence, meeting minutes, etc., relevant to the case.

Primary sources are strongest in combination. Interviewing the person, their family, and their teachers about the same event exposes disagreements a single account would hide.

A single investigator supplying all the primary data is the weakest arrangement of all. John Money’s decade of consultations with the Reimer twins rested chiefly on his own observations and reports. Nothing independent checked them for years (Diamond & Sigmundson, 1997).

2. Secondary sources

• News/Media – News coverage of events related to the case study.
• Academic articles – Journal articles, dissertations etc. that discuss the case.
• Government reports – Official data and records related to the case context.
• Books/films – Books, documentaries or films discussing the case.

Secondary sources are second-hand, so trace every claim in them back to its origin before you rely on it. A textbook can repeat a researcher’s own account for years without ever testing it.

They can also carry what the original write-up left out. John Colapinto’s biography As Nature Made Him (2000) documented the distress that Money’s published reports on the Bruce/Brenda case had omitted.

3. Archival records

Searching historical archives, museum collections and databases to find relevant documents, visual/audio records related to the case history and context.

Public archives such as newspapers, organizational records, and photographic collections can all hold relevant information. They help shed light on attitudes, cultural perspectives, and historical practices relevant to psychology.

Archives hold something an interview cannot. A record written at the time, by people who did not yet know how the story would end, does not shift with memory.

That permanence lets someone else check a published case years later. Diamond and Sigmundson (1997) read the Reimer medical file against what Money had published, and the two accounts did not match.

4. Organizational records

Organizational records offer the advantage of often having large datasets collected over time that can reveal or confirm psychological insights.

Of course, privacy and ethical concerns regarding confidential data must be navigated carefully.

However, with proper protocols, organizational records can provide invaluable context and empirical depth to qualitative case studies exploring the intersection of psychology and organizations.

• Organizational psychology: Employee surveys, turnover data, policies, and incident reports can reveal job satisfaction, workplace culture, leadership problems, and employee behavior.
• Clinical psychology: Therapists/hospitals may grant access to anonymized medical records to study aspects like assessments, diagnoses, treatment plans etc. This could shed light on clinical practices.
• School psychology: Studies could utilize anonymized student records like test scores, grades, disciplinary issues, and counseling referrals to study child development, learning barriers, effectiveness of support programs, and more.

How Do I Write a Case Study in Psychology?

Follow specified case study guidelines provided by a journal or your psychology tutor. General components of clinical case studies include: background, symptoms, assessments, diagnosis, treatment, and outcomes.

Interpreting the information means the researcher decides what to include or leave out. A good case study should always clarify which information is the factual description and which is an inference or the researcher’s opinion.

1. Introduction

• Provide background on the case context and why it is of interest, presenting background information like demographics, relevant history, and presenting problem.
• Compare briefly to similar published cases if applicable. Clearly state the focus/importance of the case.
• State the question the case is meant to answer, and say what evidence would count as answering it.
• Confirm informed consent and remove identifying details. Published case reports are normally anonymised, as Money’s were.
• Say who gathered the data and in what role. A reader needs to know whether the author was also the treating clinician.

2. Case Presentation

• Describe the presenting problem in detail, including symptoms, duration, and impact on daily life.
• Include client demographics like age and gender, information about social relationships, and mental health history.
• Describe all physical, emotional, and/or sensory symptoms reported by the client.
• Use patient quotes to describe the initial complaint verbatim. Follow with full-sentence summaries of relevant history details gathered, including key components that led to a working diagnosis.
• Summarize clinical exam results, namely orthopedic/neurological tests, imaging, lab tests, etc. Note actual results rather than subjective conclusions. Provide images if clearly reproducible/anonymized.
• Clearly state the working diagnosis or clinical impression before transitioning to management.

3. Management and Outcome

• Indicate the total duration of care and number of treatments given over what timeframe. Use specific names/descriptions for any therapies/interventions applied.
• Present the results of the intervention, including any quantitative or qualitative data collected.
• For outcomes, utilize visual analog scales for pain, medication usage logs, etc., if possible. Include patient self-reports of improvement/worsening of symptoms. Note the reason for discharge/end of care.

4. Discussion

• Analyze the case, exploring contributing factors, limitations of the study, and connections to existing research.
• Analyze the effectiveness of the intervention, considering factors like participant adherence, limitations of the study, and potential alternative explanations for the results.
• Identify any questions raised in the case analysis and relate insights to established theories and current research if applicable. Avoid definitive claims about physiological explanations.
• Offer clinical implications, and suggest future research directions.

5. Disclosures, References, and Figures

• Thank specific assistants for writing support only. No patient acknowledgments.
• References should directly support any key claims or quotes included.
• Use tables/figures/images only if substantially informative. Include permissions and legends/explanatory notes.
• Declare any conflict of interest, including your own stake in the treatment or theory the case is used to support.
• Report the observations that do not fit your interpretation. Leaving them out is how a published case study misleads a field.

Strengths of the Case Study Method

• Rich Detail: Provides detailed, richly qualitative information about the case.
• Insight: Generates insight and ideas for further research.
• Otherwise Impractical: Permits investigation of situations that would be impractical or unethical to study any other way.

Case studies let a researcher investigate a topic in far more detail than a large-sample (nomothetic) study allows. A nomothetic approach aims to ‘average’ across many participants, trading depth for breadth.

Case studies take an in-depth, multi-sided approach. This lets them shed light on aspects of human thinking and behavior that would be unethical or impractical to study any other way.

Research that only looks into measurable behavior is unlikely to capture the subjective dimension of experience. This subjective dimension matters to psychoanalytic and humanistic psychologists.

Case studies are often used in exploratory research. They can help us generate new ideas (that might be tested by other methods). They are an important way of illustrating theories and can help show how different aspects of a person’s life are related to each other.

The method is, therefore, important for psychologists who adopt a holistic point of view (i.e., humanistic psychologists).

Limitations of the Case Study Method

• Limited Generalizability: Findings lack scientific rigor and provide little basis for generalizing results to the wider population.
• Researcher Bias: A researcher’s own subjective feelings may influence the case study.
• Hard to Replicate: The unique, in-depth nature of each case makes replication difficult.
• Time and Cost: Case studies are time-consuming and expensive to conduct.
• Resource Limits: The volume of data, combined with time restrictions, can limit the depth of analysis possible.

A case study deals with only one person, event, or group. The sample size is one. We can never be sure that case represents the wider body of “similar” instances, so its conclusions may not transfer.

Case studies rest on the analysis of qualitative (i.e., descriptive) data. A lot therefore depends on how the psychologist interprets what she has gathered.

That leaves wide scope for subjective bias. A psychologist’s own opinions can intrude on what the data are taken to mean, as critics have argued of the Anna O case.

For example, Freud has been criticized for producing case studies in which the information was sometimes distorted to fit particular behavioral theories (e.g., Little Hans).

This is also true of Money’s interpretation of the Bruce/Brenda case study (Diamond & Sigmundson, 1997) when he ignored evidence that went against his theory.

The Bruce/Brenda Case Study

Aim: John Money used Bruce Reimer’s case to test his biosocial theory of gender. The theory held that identity follows the sex a child is raised as, not chromosomes or hormones (Money & Ehrhardt, 1972). His identical twin, raised as a boy, was the control.

Method: After a circumcision accident destroyed his penis in infancy, Bruce was surgically reassigned female at about 22 months, renamed Brenda, and raised as a girl. Money tracked the twins in annual consultations for roughly a decade and never told Bruce the truth about his birth.

Results: Money reported the reassignment a success for years. In reality, Brenda rejected the female identity from early childhood and was in psychological distress throughout adolescence.

Conclusion: An independent follow-up by Diamond and Sigmundson (1997) found the reassignment had failed, revealing that Money’s original findings had omitted the child’s unhappiness. The case shows how a single, invested researcher’s unchecked self-report can mislead an entire field for decades.

References

Breuer, J., & Freud, S. (1895). Studies on hysteria. Standard Edition 2: London.

Colapinto, J. (2000). As nature made him: The boy who was raised as a girl. HarperCollins.

Curtiss, S. (1981). Genie: The case of a modern wild child.

Diamond, M., & Sigmundson, H. K. (1997). Sex reassignment at birth: Long-term review and clinical implications. Archives of Pediatrics & Adolescent Medicine, 151(3), 298–304. https://doi.org/10.1001/archpedi.1997.02170400084015

Freud, S. (1909a). Analysis of a phobia of a five year old boy. In The Pelican Freud Library (1977), Vol 8, Case Histories 1, pages 169-306

Freud, S. (1909b). Bemerkungen über einen Fall von Zwangsneurose (Der “Rattenmann”). Jb. psychoanal. psychopathol. Forsch ., I, p. 357-421; GW, VII, p. 379-463; Notes upon a case of obsessional neurosis, SE, 10: 151-318.

Harlow J. M. (1848). Passage of an iron rod through the head. Boston Medical and Surgical Journal, 39, 389–393.

Harlow, J. M. (1868). Recovery from the Passage of an Iron Bar through the Head. Publications of the Massachusetts Medical Society. 2 (3), 327-347.

Money, J., & Ehrhardt, A. A. (1972). Man & woman, boy & girl: The differentiation and dimorphism of gender identity from conception to maturity. Johns Hopkins University Press.

Money, J., & Tucker, P. (1975). Sexual signatures: On being a man or a woman.