Skip to main content

On Being Sane in Insane Places: David Rosenhan and his Thud Experiment

On Being Sane in Insane Places: David Rosenhan and his Thud Experiment

David Rosenhan, 1973. 

The “Rosenhan Experiment” or Thud experiment was a study conducted to determine the validity of the psychiatric diagnosis. The participants feigned hallucinations to enter psychiatric hospitals but acted usually afterward. They diagnosed them with psychiatric disorders and gave them antipsychotic medication. David Rosenhan, a Stanford University professor, conducted this study, and published it in the journal Science in 1973 under the title “On Being Sane in Insane Places”.

Some consider it an essential criticism of psychiatric diagnosis and broach wrongful involuntary commitment. Rosenhan did the study in eight parts. The first part involved using healthy associates or “pseudopatients” (three women and five men, including Rosenhan himself) who briefly feigned auditory hallucinations to gain admission to twelve psychiatric hospitals in five states in the United States. They admitted all and were diagnosed with psychiatric disorders. After admission, the pseudopatients acted usually and told staff that they no longer experienced any other hallucinations. As a condition of their release, they forced all the patients to admit to having a mental illness and had to agree to take antipsychotic medication. The average time that the patients spent in the hospital were 19 days. They diagnosed all but one with schizophrenia “in remission” before their release. The second part of his study involved a hospital administration challenging Rosenhan to send pseudopatients to its facility, whose staff asserted that they could detect them.

Rosenhan agreed, and they found in the following weeks forty-one out of 193 new patients as potential pseudopatients, with 19 of these receiving suspicion from at least one psychiatrist and one other staff member. Rosenhan sent no pseudopatients to the hospital. While listening to a lecture by R. D. Laing, associated with the anti-psychiatry movement, Rosenhan conceived the experiment to test the reliability of psychiatric diagnoses. The study concluded that “we cannot distinguish the sane from the insane in psychiatric hospitals” and illustrated the dangers of dehumanization and labelling in psychiatric institutions. It suggested that using community mental health facilities that concentrated on specific problems and behaviours rather than psychiatric labels might be a solution. It recommended education to make psychiatric workers more aware of the social psychology of their facilities.

The procedure

Pseudopatients called the hospital and asked for an appointment -arrived at the admissions office saying that they were hearing voices-voices were unclear but seemed to say either empty, hollow, or thud. They chose these words to emphasize the person’s life-other than changing their name or profession. Their personal history was accurate. There was no existence of any previous or current pathological behaviour admitted, and the pseudopatients stopped displaying any symptoms of abnormality. Some were nervous, not believing they would accept them so readily, but otherwise, they would behave as they usually would. The staff gave them the medication they did not swallow, responded to it, and chatted with other patients. Each would have to convince the team they were sane, so they would release them. Rosenhan measured the number of days it took for their release to take place. All but one wanted to leave the hospital at once, so they all complied to act normally and abiding by the instructions from the staff. The pseudopatients made notes of observations about their time on the ward. Initially, they would do these in private, but then out in the ward’s openness when they realized that the staff was not suspicious of the behaviour.

Results of the Study

They diagnosed all but one pseudopatient with schizophrenia (the other with the bipolar depressive disorder). They admitted all of them to the hospital and discharged each with a diagnosis of schizophrenia in remission. (i.e. Symptoms were not present at the time of release) the length of hospitalization varied from 7 to 52 days, with an average of 19 days. They never detected pseudopatients, no records or behavior by hospital staff showed that there were any doubts over the authenticity of the patients’ visitors and other patients recognized that some pseudopatients were sane. During the first three hospitalizations, 35 out of 118 patients on the admissions wards voiced their suspicions, such as you are not crazy. You are a journalist or a professor. 


Failure to detect sanity may be because doctors are more likely to favour a type 2 error (they are more likely to diagnose a healthy person as sick) than a type 1 error (than a sick person as healthy) less dangerous this works for medicine but is not necessarily the case for psychiatry as once we label a person as being mentally ill, it is challenging to shift the label the fact that some patients noticed the pseudopatients were sane when the staff did not raise important questions perhaps the results seem to suggest that diagnosis is reliable as they gave all but one individual a diagnosis of schizophrenia when presenting similar symptoms discharge of schizophrenia in remission when they were not actually suffering from any known disorder (affects reliability)it is interesting to note that the staff interpreted many of the pseudo-patients behaviours as being in line with the symptoms of the condition they had diagnosed them with. Rosenman believed that once given a label, we overlook all normal behaviours. For example, they saw their notetaking as an aspect of their pathological behaviour. Staff wrote in one patient’s notes: the patient engages in writing behaviour.

Second Experiment

Another hospital had heard of the findings of the first part of the study, and the staff over there did not believe the results would have occurred in their hospital. Rosenhan informed the staff that in the next three months, one or more pseudopatients would try again to gain entry to the hospital each member of staff was asked to rate every patient (either at admission or on the ward) who wanted admission on a scale from 1 to 10 in terms of whether they thought the patient was a real or fake score of 1 reflected an elevated level of confidence that the patient was fake. Over the 3 months, 193 patients tried to gain admission.

  1. What was the aim of Rosenhan?

  • He wanted to test the reliability of a mental health diagnosis, to see if medical professionals could tell the sane from insane. 

  1. Was Rosenhan’s experiment or the Thud experiment an experiment?

No, it was an observational study. 

Who were the participants of the thud experiment?

The participants were staff and patients at the twelve hospitals.

Where were the hospitals of Rosenhan’s experiment?

In five states on the East and West coasts of the US. 

Who knew about the pseudopatients in the Thud experiment?

The hospital administrator and chief psychologist

How many pseudopatients were they, and who were they?

8 (3 women and five men) confederates.

Was Rosenhan a pseudo-patient?

Yes, Rosenhan also volunteered as a pseudopatient.

How would patients leave the hospital?

They had to convince the staff they were sane.

What did patients act like when they were admitted them?

They behaved like normal individuals. 

What did the staff do once in the wards?

Took notes. 

Were notes taken in the open?

Only once they were sure staff were not suspicious

What words they chose as the voices?

Thud, empty, and hollow.

What did they change about the patient’s information?

Just the name and occupation, all personal backgrounds stayed the same

How did patients contact the hospital?

Called them up.

What did patients report?

Hearing voices

What did Rosenhan measure?

How many days it took for the psychiatrists to release the patients.

Did they give the patients drugs?

Yes, but they did not swallow the medications. 

What were the patients diagnosed with?

11 schizophrenia and 1 manic depressive disorder

What did the average days of stay in the hospital?


Who many days did it vary by?

Were patients detected?

No, no evidence or records that staff doubted the authenticity

How many of the patients on the ward voiced their concerns?


What did real-life patients say?

‘You’re not crazy, you’re a journalist. 

How many were admitted to hospitals?


What is a type 2 error?

Diagnose a healthy person as sick

What is a type 1 error?

Diagnosing a sick person as healthy

What error did the doctors make?

Type 2

Why did they make this type of error?

Considered less dangerous?

What is the problem with a type 2 error in mental health?

Hard to move the stigma

Why was it thought that even when behaving normally they were not let out?

Once given a label, they overlook all normal behavior.

Is reliability good?

Could be said to be as all same diagnosis but did not have it

What was the aim of his second study?

To investigate if we could reverse the tendency to diagnose sane as insane.

Why did a second experiment take place?

They said that the results in the first one would not happen in theirs.

What did Rosenhan inform the hospital in experiment two?

That he would send one or more pseudopatients in over the course of three months

What were the staff asked to do in experiment-two?

Rate patients on a scale of 1-10 of how real they were (1 being fake)

How many patients tried to gain admission during experiment two?


How many patients did Rosenhan send in for the second experiment?


How many patients did they judge as fake in the second experiment?


How many did one psychiatrist suspect in the experiment two?


What is the conclusion?

The results show issues with the reliability and validity of diagnosis and strongly suggest that it is not possible to detect the sane from the insane, as staff members could not identify that none of the patients were pseudopatients

What do the results show?

Issues with reliability and validity

When did the study take place?



  1.  Gaughwin, Peter (2011). “On Being Insane in Medico-Legal Places: The Importance of Taking a Complete History in Forensic Mental Health Assessment”. Psychiatry, Psychology, and Law. 12(1): 298–310. doi:10.1375/pplt.12.2.298. S2CID 53771539.
  2. Rosenhan, David (19 January 1973). “On being sane in insane places”. Science. 179 (4070): 250–258. Bibcode:1973Sci...179..250R. doi:10.1126/science.179.4070.250. PMID 4683124. S2CID 146772269. Archived from the original on 17 November 2004.
  3. Slater, Lauren (2004). Opening Skinner’s Box: Great Psychological Experiments of the Twentieth Century. W. W. Norton. ISBN 0-393-05095-5.
  4. Kornblum, William (2011). Mitchell, Erin; Jucha, Robert; Chell, John (eds.). Sociology in a Changing World (Google Books)(9th ed.). Cengage learning. p. 195. ISBN 978-1-111-30157-6.
  5. Spitzer, Robert (October 1975). “On pseudoscience in science, logic in remission, and psychiatric diagnosis: a critique of Rosenhan’s “On being sane in insane places””. Journal of Abnormal Psychology. 84 (5): 442–52. doi:10.1037/h0077124. PMID 1194504. S2CID 8688334.
  6. Abbott, Alison (29 October 2019). “On the troubling trail of psychiatry’s pseudopatients stunt”. Nature. 574 (7780): 622–623. Bibcode:2019Natur.574..622A. doi:10.1038/d41586-019-03268-y. “But some people in the department called him a bullshitter,” Kenneth Gergen says. And through her deeply researched study, Cahalan seems inclined to agree with them.
  7. Temerlin, Maurice (October 1968). “Suggestion effects in psychiatric diagnosis”. The Journal of Nervous and Mental Disease. 147 (4): 349–353. doi:10.1097/00005053-196810000-00003. PMID 5683680. S2CID 36672611.
  8. Loring, Marti; Powell, Brian (March 1988). “Gender, race, and DSM-III: a study of the objectivity of psychiatric diagnostic behavior”. Journal of Health and Social Behavior. 29 (1): 1–22. doi:10.2307/2137177. JSTOR 2137177. PMID 3367027.
  9. Moran, Mark (7 April 2006). “Writer Ignites Firestorm With Misdiagnosis Claims”. Psychiatric News. American Psychiatric Association. 41 (7): 10–12. doi:10.1176/pn.41.7.0010. ISSN 1559-1255.



Popular posts from this blog

ADVOKATE: A Mnemonic Tool for the Assessment of Eyewitness Evidence

ADVOKATE: A Mnemonic Tool for Assessment of Eyewitness Evidence A tool for assessing eyewitness  ADVOKATE is a tool designed to assess eyewitness evidence and how much it is reliable. It requires the user to respond to several statements/questions. Forensic psychologists, police or investigative officer can do it. The mnemonic ADVOKATE stands for: A = amount of time under observation (event and act) D = distance from suspect V = visibility (night-day, lighting) O = obstruction to the view of the witness K = known or seen before when and where (suspect) A = any special reason for remembering the subject T = time-lapse (how long has it been since witness saw suspect) E = error or material discrepancy between the description given first or any subsequent accounts by a witness.  Working with suspects (

ICD-11 Criteria for Anorexia Nervosa (6B80)

ICD-11 Criteria for Anorexia Nervosa (6B80) Anorexia Nervosa is characterised by significantly low body weight for the individual’s height, age and developmental stage that is not due to another health condition or to the unavailability of food. A commonly used threshold is body mass index (BMI) less than 18.5 kg/m2 in adults and BMI-for-age under 5th percentile in children and adolescents. Rapid weight loss (e.g. more than 20% of total body weight within 6 months) may replace the low body weight guideline as long as other diagnostic requirements are met. Children and adolescents may exhibit failure to gain weight as expected based on the individual developmental trajectory rather than weight loss. Low body weight is accompanied by a persistent pattern of behaviours to prevent restoration of normal weight, which may include behaviours aimed at reducing energy intake (restricted eating), purging behaviours (e.g. self-induced vomiting, misuse of laxatives), and behaviours aimed at incr

ICD-11 Criteria for Schizophrenia (6A20 )

ICD-11 Criteria for Schizophrenia (6A20 ) Schizophrenia is characterised by disturbances in multiple mental modalities, including thinking (e.g., delusions, disorganisation in the form of thought), perception (e.g., hallucinations), self-experience (e.g., the experience that one's feelings, impulses, thoughts, or behaviour are under the control of an external force), cognition (e.g., impaired attention, verbal memory, and social cognition), volition (e.g., loss of motivation), affect (e.g., blunted emotional expression), and behaviour (e.g., behaviour that appears bizarre or purposeless, unpredictable or inappropriate emotional responses that interfere with the organisation of behaviour). Psychomotor disturbances, including catatonia, may be present. Persistent delusions, persistent hallucinations, thought disorder, and experiences of influence, passivity, or control are considered core symptoms. Symptoms must have persisted for at least one month in order for a diagnosis of schi