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In this article we will discuss about the diagnostic aids used for psychiatric patients.
With the advances in biological psychiatry, there has been a renewed interest in the potential application of laboratory test evaluations for psychiatric patients.
Reasons for this growing interest is due to many factors i.e.:
i. An increasing sensitivity of psychiatrists to physical conditions that can give rise to psychiatric symptoms.
ii. Growing use of the laboratory to monitor some of the biological therapies currently used in psychiatry
iii. Neurosciences have been accumulating evidence for subtle neurophysiologic dysfunction in many psychiatric disorders, and an effort is being made to quantify some of these abnormalities.
The laboratory tests have many functions.
Some of these are listed in Table 5.1:
Psychological Tests:
These tests provide a relatively standardized objective measurement of certain aspects of the patients such as intelligence, personality, memory, symptom profile etc.
Aims:
The main aims of psychological assessment include:
i. Clarify diagnostic uncertainty.
ii. Specify the severity of symptoms and other difficulties.
iii. Assess patient strengths.
iv. Measure cognitive functioning.
v. Inform differential treatment assignment.
vi. Focus the therapeutic intervention
vii. Role-include the patient into a therapeutic stance, i.e. interest in his own strengths and areas needing assistance.
viii. Monitor treatment response.
Methods:
The psychological evaluation depends on collecting information by:
(a) Document studies:
Document studies case notes which are retrospective, official studies e.g. census etc.
(b) Mail questionnaires:
Mail questionnaires cheap and easy but slow response rate, hence it is sample biased.
(c) Self-rating questionnaires:
Self-rating questionnaires cheap, easy, sensitive to changes but may be answered inaccurately due to misunderstanding. These questionnaires cannot be complex.
(d) Observer rated interview:
Observer rated interview may be structured, semi structured or informal. Allow great flexibility and accuracy but are expensive, and require training.
Sources of Error:
i. Response set:
Subject (patient) always tends either to agree or disagree with questions.
ii. Bias towards centre:
Subject tends to choose the middle response and shun extremes (e.g. in a questionnaire with three choices to every “Nil” “Occasionally” and “often”, the subject answers “Occasionally” more often).
iii. Social acceptability:
Subject chooses the acceptable answer rather than the true one.
iv. Halo effect:
The answers are chosen to ‘fit’ with previously chosen answers; response become what is expected by the observer.
v. Hawthorne effect:
Researchers alter the situations by their presence.
Areas of Assessment:
The major areas of assessment include:
i. Cognition
ii. Personality traits and disorders
iii. Personality Psychodynamics (Projective and objective tests)
iv. Enabling factors for treatment
v. Symptoms of various psychiatric disorders
vi. Environmental demands and social adjustment.
A. Cognition:
i. Stanford-Binet Scale:
The French psychologist Alfred Binet and Physician Theodore Simon developed this scale in 1905. The 30 items comprising this 1905 scale were arranged in ascending order of difficulty. In 1908 revision, Binet and Simon introduced the concept of Mental Age. The intelligence quotient (I.Q.) was proposed by William Stern in 1912 and incorporated by Lewis Terman (1916).
The ratio I.Q. was measured by formula:
Unlike the Wechsler-Bellevue Scales, the same items are not administered to and scored for all subjects; each age level is defined by a series of items which measure various intellectual capacities. The score is expressed in terms of both I.Q. and mental age attained over all the test items.
ii. Wechsler Adult Intelligence Scale (WAIS):
Wechsler Adult Intelligence Scale (WAIS) David Wechsler, American Psychologist in 1939. It is one of the most commonly utilized test to measure adult intelligence. It is used in age group from 16 years to adulthood.
Components:
It has two major scales with subtests i.e.:
Verbal scale reflects retention of previously acquired (and frequently overlearned) factual information and the performance scale reflects visuospatial capacity and visuomotor speed on relatively novel problems. Neurologically normal but culturally disadvantaged persons may obtain a relatively low verbal I.Q. (e.g. because of a limited range of information and vocabulary) whereas it is not unusual for highly educated and widely read persons to have a particularly high verbal I.Q. The performance scale is less dependent on formal education but appears to be more sensitive to normal aging. The discrepancy between Verbal I.Q. and Performance IQ is generally less than 15 points.
Specific impairment on the Performance Scale occurs in patients with right hemisphere (particularly posterior) lesions.
Exceptions:
A physical handicap, neurological deficit, abnormal behaviour or cultural differences may necessitate modification of standard testing procedures or substitution of other cognitive tests such a Leiter Scale and Raven’s Progressive Matrices (for patients with deafness or auditory agnosias) or Peabody Picture Vocabulary test (for patients unable or unwilling to speak or cooperative with WAIS).
The tests used of neuropsychological assessment in clinical psychiatric settings is best described as the identification of behaviour deficits most likely associated with established patterns of organic impairment.
Purposes:
The uses of neuropsychological testing include:
i. Learning disabilities in children and adolescents.
ii. Neurological disorders (e.g. head injury, dementia, epilepsy etc.)
iii. Emotional and attentional disorders.
Tests:
i. Bender (Visual Motor) Gestalt Test:
The most widely employed graphic test of constructional apraxia (inability to copy the figures given) appropriate for administration to both children and adults (5 years to adulthood). It was developed in 1938 by Lauretta Bender) for assessing maturational levels in children. The test material consists of nine figures (Items A and 1 to 8). This test is interpreted from i. 2 types of errors
(a) Closing-in-phenomenon:
Patient uses pan of the model to be copied in making construction.
On the basic of IQ, the population is divided into 7 groups as shown in Table 5.2:
(b) Visual neglect:
Partial or total failure to copy left half of the construction (indicate unilateral spatial inattention or neglect associated with right hemisphere disease)
ii. Memory problem:
Failure to repeat of Bender designs after 45-60 seconds indicate memory problem and need further specific test for memory.
The other tests used for neuropsychological assessment are given in Table 5.3:
B. Assessment of Personality Traits and Disorders:
The personality traits need assessment to develop a treatment plan for various reasons e.g.,
(a) Traits or disorders may be the focus of intervention.
(b) Traits may either help or hinder the development of a therapeutic relationship with the patient.
(c) Traits may exacerbate or be related to the incidence of certain symptoms (e.g. depression).
Some of the widely used and psychometrically sound instruments available for assessment of personality are given in Table 5.4:
C. Assessment of Personality Psychodynamics (Projective and Objective Tests):
The term ‘projective test’ (based typically on Ego’s defense mechanism — Projection) was coined by L.K. Frank. These tests are used to assess the psychodynamic factors as drives, unconscious wishes, conflicts and defenses. The importance of providing information about personality dynamics and structure that are outside the conscious awareness of the patient is the most important rationale for using these tests. The most widely used tests are – Rorschach Inkblot Test, Thematic Appreciation Test (TAT) and Minnesota Multiphasic Personality Inventory (MMPI).
The other used tests are—Children Apperception Test (CAT), Sentence Completion Test (SCT), Symptom Checklist-90 (SC-90), Figure Drawing etc.
Some of the Projective and Objective tests used for adults are given in Table 5.5:
D. Assessment of Enabling Factors for Treatment:
In clinical practice, accurate diagnosis is not sufficient for determining optimal, specific treatments. The optimal treatment depends on many other non-diagnostic factors which include characteristics of the patient that will affect the acceptance, utilization and absorption of the treatment that is recommended.
Unfortunately, this area of assessment has been insufficiently attended to by clinical psychologists. Findings from the traditional tests have been used unsystematically to make inferences that may be of some assistance in treatment planning. These include inferences concerning degree of insight, psychological sophistication, and defensive alignment.
Psychological tests can be used for assessing these dimensions as given in Table 5.8:
E. Assessment of Symptoms:
The major constellations of symptoms that may require assessment include anxiety, elation and depression; thought disorder; suicidal intentions/ behaviours; aggressive behaviours, and substance abuse including abuse of food, alcohol and drugs.
There are a number of instruments that have been developed for the assessment of a wide variety of symptoms.
Some of them are given in Tables 5.9 and 5.10:
F. Assessment of Environment Demands and Social Adjustment:
The interaction between the patients and the pressures of the environments has been studied in many diseases but the most important are with coronary heart disease (Jenkins Activity Survey), schizophrenia (how expressed emotions affects the course of schizophrenia), marital and social adjustments.
Some of these instruments are given in Table 5.11:
