How can you assess and diagnose abnormality? - Chapter 3 (Abnormal Psychology)

An assessment is the process of collecting symptoms and seeing what causes them. A diagnosis is a label for a number of symptoms that often occur together.

There are modern methods for diagnosing. Assessment techniques must be valid and reliable. In addition, they must be standardized.


To say that a test is valid: the test must actually measure that for which it was designed. The validity for testing psychological disorders is not very large, because there are no good objective methods for determining these.

There are different types of validity:

  • Face validity: when the test is valid at first sight.
  • Content validity: the extent to which a test measures the important aspects of the phenomenon to be investigated and omits the less important aspects.
  • Competitive validity: the extent to which the test gives the same result as other, similar tests that measure the same construct.
  • Predictive validity: the extent to which a test can predict how a person thinks, acts or feels in the future.
  • Construct validity: the extent to which the test measures what it needs to measure, instead of something completely different.


The reliability is the certainty that the outcome of the measurement remains the same. Different types of reliability:

  • Test-retest reliability: how reliable the results of the test are over time.
  • Alternate form reliability: using different forms of the test when it has to be taken again.
  • Internal reliability: visible by splitting a test into two or more parts, to determine whether the answers of people on one part are comparable to those on the other part.
  • Interrater / interjudge reliability: if different people take the test, the outcome of the test must remain the same.


To prove validity and reliability, you can standardize the data collected of a test, so that there is no variation between tests in how this is done.

Clinical interviews

A lot of information for an assessment comes from an interview, which often includes an investigation into the mental status.

There are five types of information:

  1. Prevention and behavior: does the patient look cared for or not, and how does the patient behave, does he look at you or go away.
  2. Thought processes
  3. Mood and affect: does the patient seem depressed?
  4. Intellectual functioning
  5. Is the person well-oriented: does he know who she is and where he or she is and what the time and date are?

Clinicians increasingly use structured interviews: a series of questions about the symptoms.

Symptom questionnaire

In order to quickly determine what the symptoms are, a symptom questionnaire can be filled out. A frequently used questionnaire is the Beck Depression Inventory (BDI): here you have to judge for yourself which description best suits how you felt during the past week.

Personality Inventory

Personality inventories are questionnaires that look at the typical way of thinking, feeling and behaving of a person. An example is the Minnesota Multiphasic Personality Inventory (MMPI): the patient must indicate whether a statement is correct, incorrect or that they can not be assessed. The questionnaire is empirically developed, which means that the questions were asked first to healthy subjects and then to people with mental health problems. The items on which the answers differed were included in the Inventory.

There are also validity scales that check whether a person completes the test fairly.

A disadvantage of the MMPI is that this questionnaire was developed in America and may therefore not be representative of the rest of the world. No good, representative sample was used.

Behavioral observation and self-monitoring

Clinicians often use behavioral observations to see how patients approach situations. They look at specific behavior and cause that behavior to be caused. An advantage is that you look at 'natural' behavior and not at a self-report of the behavior by the patient. A disadvantage is that people know that they are observed and behave differently, this is called reactivity. Moreover, this method is not objective. That is why the situation must be standardized.

People can also apply self-monitoring, while keeping track of how often they perform a certain action per day and in which circumstances this happens. The advantage of self-observation is that people do not change their behavior because of the presence of another person (reactivity).


Tests measure the intellectual strength of an individual. These tests are used in schools, in the army and in job applications. The WAIS (for adults) and WISC (for children) measure the basic intelligence capacity. However, we still do not know exactly what intelligence means, there is no good definition.

There is also a bias in the test: the test was developed for and by Western countries and this can influence the result when the test is taken from someone who comes from a non-Western country.

Neurological testing

A neuropsychological test is used when clinicians suspect a neurological disorder, such as memory problems. An example of this is the Bender-Gestalt Test. The therapist assesses the sensorimotor skills of the patient by having him draw nine pictures. People with brain damage can not reproduce the drawings.

Brain-imaging techniques

Brain-imaging (brain imaging) is often used to detect brain damage and to search for possible brain tumours. We look at differences in structures of the brain.

Possible methods are:

  • Computerized tomography (CT): X-rays pass through the head of the patient from different angles. The level of radiation absorbed by the brain is measured and from these measurements the computer forms a three-dimensional image of the most important brain structures.
  • Positron-emission tomography (PET): a picture of the activity of the brain. A radioactive isotope is injected through the blood into the brain. The more active a particular brain region, the more blood flows there to supply oxygen and supply the brain with energy. Positions of the isotope collide with electrons and become photons that each go in a different direction. The PET scan can see these photons and therefore sees which areas in the brain are most active.
  • Single photon emission computed tomography (SPECT): the SPECT has the same effect as a PET scan, but another substance is injected. This is less expensive, but unfortunately also less accurate.
  • Magnetic resonance imaging (MRI): this does not require a radioactive substance, so this method can be used more often by the same person. MRI gives a three-dimensional image of the brain through a magnetic field, which ensures that atoms are brought out of balance for a very short time. The MRI scan registers this and measures the time that elapses before the atoms return to their normal position. Each molecule has a different structure and therefore also a different 'reaction time'. The MRI can convert this into images of the brain.
  • Psychophysiological tests. Psychophysiological tests are an alternative method for brain-imaging tests. An electroencephalogram (EEG) measures electrical activity around the cerebral cortex. Clinicians compare the results obtained with those of people who do not have psychological problems. Measuring heart rhythm is also a psychophysiological test. The tests are used to map emotional and psychological changes.
  • Projective testing. A projective test is based on the assumption that when people are confronted with an ambiguous stimulus (such as a strangely shaped inkblot), they want to interpret it on the basis of their current concerns and feelings, their relationships with other people and their inner conflicts or desires. This is used to bring up unconscious matters. A well-known test is the Rorschach Inkblot Test, which consists of ten cards with a symmetrical ink dot that has no clear meaning. People have to say what they see in the dot, everyone sees something else again. Another test is the Thematic Apperception Test (TAT): you get to see a series of images and then say what kind of story the pictures tell. Especially clinicians working from the psychodynamic perspective use projective tests to investigate underlying conflicts and concerns in patients. Other clinicians doubt the usability of the tests because the reliability and validity do not seem to be strong.

Challenges in diagnosing

One of the biggest challenges in diagnosing is when an individual refuses to give information. Someone can refuse to give information because that person does not want to be assessed and / or treated. Often people have a certain interest in the outcome of the test and therefore give information that is in their 'advantage' (bias). This arises, for example, when assessments are part of a lawsuit, for example when parents fight for the custody of their children. Challenges can arise when children or people from different cultures are evaluated.

Evaluating children

A conversation with a sad, stressed child often does not go as it should, you often do not get a real answer to your question. Children can not describe their feelings about certain things in the same way as adults, certainly not in connection with a certain event. Clinicians must therefore rely on others, parents for example. They are often asked about changes in behavior in recent times. Unfortunately, parents are not always accurate and often they are biased. Sometimes parents bring their children to psychologists, while in fact they would benefit more from treatment themselves. In addition, parents can also be the cause of the child's problems. Teachers can also give information about children, they often see first that a child has problems.

Evaluating individuals in different cultures

People who emigrated to another country often do not speak the same language as their new compatriots, or do not speak the language well enough. This can ensure that someone is under or over diagnosed. A translator can be used, but often gives an interpretation to the questions and answers and is not literally in his translations. In this way misunderstandings can arise and the therapist can not make the correct diagnosis.

There are also cultural prejudices (bias): people speak the same language, but have a different cultural background. Symptoms may be slightly more severe. This is because people in other cultures often think differently.


A diagnosis is a label that we give to symptoms that occur more often together. A set of symptoms is called a syndrome, which is an observable manifestation of an underlying biological disorder. We have to pay attention to behavior that can be a symptom and also how often that behavior is repeated.

Often, symptoms overlap between different syndromes. Therefore, you have to have different symptoms to be diagnosed with a certain syndrome. A classification system contains all known syndromes and gives clear rules to be able to establish them with the patient. Classifying is therefore the classification of problems of individuals in certain groups.

Hippocrates was the first to establish syndromes. His syndromes were: mania, melancholy, paranoid and epilepsy.

Now we have the DSM: Diagnostic and Statistical Manual of Mental Disorders. This contains all syndromes and disorders with the associated symptoms to be able to give a correct diagnosis.

Diagnostic and Statistical Manual of Mental Disorders

The DSM was developed in America. The first DSM came out in 1952, containing all known psychological disorders of that time. The criteria for diagnosing were also given. The criteria were then vague descriptions, which were heavily influenced by the psychoanalytic theory. The reliability of DSM-I and also DSM-II was therefore very low.


The DSM-IV differs very little from the DSM-III, they are both more reliable than the first DSMs. There are specific and concrete criteria for the diagnosis: these are often well observable and measurable behaviours and feelings. Usually a person must have at least a certain number of possible symptoms to get a diagnosis. It must be known how long the symptoms are already present and daily life must be influenced by the symptoms in a negative way.

The reliability of the DSM

The reliability of the DSM-III was reasonably good, about 70%. The fact that the reliability was still not really high was due to several factors, but the most important is that the focus was on observable symptoms and not on the underlying factors.

The DSM-IV is more reliable because the criteria are tested in a clinical and research environment.

Multi-axial system

The DSM-III and DSM-IV have 5 axes (or dimensions). The first two are the only ones that reflect the actual disorders, together with the criteria required for the diagnosis. The other three are mainly meant to provide information about the physical condition, which can influence the mental state.

Axis 1: clinical disorders. On this axis, the clinician records which major disorders the patient qualifies, with the exception of mental retardation and personality disorders. Furthermore, it is noted whether these disorders are chronic or acute.

Axis 2: personality disorders and mental retardation. In general, the disorders on this axis are lifelong.

Axis 3: general medical conditions. On this axis all medical and physical conditions are recorded that a patient has. Although not all of these conditions need to affect psychological conditions, it is important that the clinician is aware of it, as well as the medication that the patient may be taking.

Axis 4: psychological problems and problems in the environment. Psychological stressors can influence the mental disorder. Again, these stressors have nothing to do with the disorder, but the clinician must be aware of it.

Axis 5: global assessment of functioning. On this axis, the clinician assesses the level at which the patient functions in daily life. This helps to determine to what extent the disorder affects the life of the patient.

An important change in the DSM-V compared to the earlier versions of the DSM is that the DSM-V no longer works with this system of axles. In this way it is brought more into line with the International Classification System of Diseases (ICD). Axis I, II and III have been returned to a general diagnostic scheme in the DSM-V. Separate notations for important psychosocial and contextual factors (previously as IV) and disabilities (formerly as V), are made by the clinician.

Continuous concerns about the DSM (possible points for improvement)

Consider the continuum: there is a clear distinction between normal and abnormal behavior in DSM-IV. Many psychologists argue for a diagnostic system that sees disorders as extremes of normal behavior, rather than as qualitatively different from normal functioning.

 It is difficult to properly distinguish between mental disorders by using the DSM-IV. Many symptoms are associated with multiple syndromes and this can cause confusion. It may be good to develop better distinctive criteria. On the other hand, there is a lot of overlap present between disorders, the natural occurrence of problems in mood, behavior and thoughts. The DSM-V deals more with the underlying dimension of the disorder but fails to properly distinguish among them.

Cultural differences: Different cultures have different ways to conceptualize mental disorders and some disorders from the DSM-IV do not occur in other cultures at all. In DSM-V, researchers try to map out cultural variation in the expression and characterization of disorders.



The danger of a diagnosis

There are many benefits when someone has received a diagnosis, but people also have many disadvantages. Szasz claims that we quickly label people who do not fit within society. Someone with a label is then treated differently, because he is abnormal according to our standards.

Rosenhan had 12 colleagues in different mental hospitals, saying that they heard voices in their heads say 'hollow', 'empty' and 'thud' (hollow, empty and broken). Actually there was nothing wrong with them, but they were indeed recorded and treated. Once they were recorded, they said that they no longer heard voices and, moreover, they wrote their experiences every day on a notepad. Some other patients had previously learned that the researchers did not actually have a mental disorder, but the institutions themselves did not find out after 19 days on average.

The label 'abnormal' is even more dangerous for children. Here is an example of an investigation with a group of boys, some of whom had a behavioral problem. The boys had to work together in pairs. On one occasion, the boys received background information about the other person, namely that the boy they worked with had a behavioral problem, the other time this did not happen. Afterwards the boys had to say how they found the cooperation. The boys who knew that their partner had a behavioral problem were less friendly and less interactive and did not like the cooperation so well. These results show that if abnormal labelling of a child can have strong effects on the behavior of other children towards this child, even when there is no reason for the child to get such a label.

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