Diagnosis and treatment planning are complicated activities that attempt to determine a course of treatment affecting an individual’s affect, thinking, behavior, and social systems. Often treatment planning decisions are made based on assessments that rely on gaining information through unstructured interview and informal observations obtained over a very short period of time. Treatment plans based on these one-dimensional assessments often ignore the complex context of a client’s problems by not collecting information from multiple environmental settings using multiple methods of measurement. Managed health care organizations are often hesitant to allow physicians to refer clients for more in-depth assessment pushing instead a strategy focused on simple, single method ratings with quick turnaround and superficial survey of symptoms. As a result, clinicians may overlook important areas of functioning and miss the context of the client’s complaints. Further difficulty occurs when using the single method, usually an interview, with children, youth, and their parents as they can be poor historians, or biased informants adding error to information collection and leading to invalid conclusions. For example, the client may have an agenda when presenting for an interview, such as obtaining medication, proving there are no problems, or affixing blame on certain individuals or circumstances. A further source of error can be the context of the interview often leading to denial or exaggeration of presenting problems. For example, if youths believe that they will have to take medication for the rest of their life, which is not to their liking, they may admit to no symptoms during the interview. Drastic diagnostic errors may occur when relying on single method assessment leading to inappropriate or inadequate treatment. This, in turn, can lead to further clinical problems and complications. In Perry’s review of the assessment literature reported in 1992, diagnosis by one clinician using a single method of assessment (semi-structured interview) can yield a 70% error in personality diagnoses when compared to a more complex integrated assessment using multiple methods of gathering information.

Psychological assessment offers a tool to improve the accuracy and reliability of diagnosis and treatment planning. Although time consuming and adding to immediate expense, in the long run, there can be savings due to fewer false starts and inappropriate treatment interventions. Not everyone needs in-depth psychological assessment. In fact, it would be too costly to provide this for every client. Yates and Taub suggested in 2003 that a clinician needs to weigh the cost/benefit for an in-depth assessment before making a referral. Psychological assessment consultations are useful when clients have complex, multiple problems; the diagnosis is unclear; the client is unresponsive to treatment attempts; the client is dissatisfied with previous mental health treatment; it is difficult to engage the client; secondary gains or symptoms are suspected;
liability risk appears to be high; and clients are seeking certain medications or medical treatments that are of questionable utility to presenting problems. Examples of common indications for psychological assessment are summarized in Table 2-1.

It is important to distinguish between psychological testing and psychological assessment. A psychological test has been defined as a systematic procedure for measuring a sample of behavior. Systematic procedure refers to the fact that the test was constructed to be administered in the same standard manner thereby minimizing sources of measurement error related to situational variables, clinician error, and clinician—client interaction error. Thus, testing is the process of administering a particular test to obtain a specific score on a relatively narrow dimension of behavior. Well-constructed tests allow for developmental and normative descriptions. For example, once the score is obtained on an attention-deficit hyperactivity disorder (ADHD) or depression rating scale, the score can be compared to a large group of individual scores previously collected and studied. The score can then inform the clinician whether it is high, average, or low for the age group represented by the client and even give critical “cutoff” scores suggesting significant presence of whatever the test measures. It allows for empirically quantified information with standardized administration, information about reliability, a validity of the construct measured, and an overall more precise measurement of client dimensions than is typically obtained with interviews. However, tests are usually a single method of measure such as self-report measures, observer ratings, and performance tasks that yield single method bias and may only measure a single construct. Again, using the simple ADHD or depression symptom checklists as examples, the rater is faced with a list of symptoms or behaviors that make up a single diagnostic construct. The rater assigns a level of disorder or quantity score to each symptom or behavior about himself or herself or someone else. The rater may actually have little knowledge of the client, only view him or her in limited settings such as in physical education class or at youth group outings, or have a biased preconceived view that influences such observations. Self-raters may have little self-awareness, be seeking certain treatments, exhibit intense denial or resistance, or have exaggerated symptoms in the narrow situational context of the single test. Thus, self-raters may give biased responses to the rating scale, possibly based on limited knowledge or distorted by personal views. Since it is a single method rating, it is difficult to examine the accuracy of the report. This can easily lead to a misdiagnosis and inadequate or inappropriate treatment interventions. Obtaining a single sample of behavior, thought, or affect through one measurement method can easily lead to making judgments that are highly inaccurate. In addition, these simple tests often do not measure a sufficient domain of behaviors to differentiate among various diagnostic subtleties. For example, when inattention is rated high on an ADHD rating scale might that not also
represent the attention problems seen with some depressed children or children with anxiety disorders? Since there were no items for rating mood behaviors, it is difficult to tease out what the inattention means.

Psychological assessment, on the other hand, comprises focusing on a number of scores obtained through multiple methods and combining the data in the context of historical information, referral information, interview data, and behavior observations in order to generate a cohesive and comprehensive understanding of the client. Thus, multiple test scores, or a battery of tests, are examined in the context of current situational circumstances, developmental history, and family social system factors. The high score obtained on a self-report ADHD scale is now compared to the low scores obtained from teachers, the high anxiety scores on a performance test, the history of average school performance, the recent episode of sexual abuse by a peer at school, and the information that a parent has recently dropped out of treatment for methamphetamine abuse. The experienced psychologist can take these multiple sources of information or samples of functioning and derive a more accurate description of the client’s diagnosis and develop a more accurate treatment plan.

In general, the use of a battery of tests that obtains information through multiple methods including self-report, information derived from performance tests, observer information, and information derived from behavioral or functional assessment strategies is more reliable and accurate than reliance on a single clinician using a single method (i.e., an interview). These psychological assessments, however, cannot be completed by a minimally trained clinician and requires an extensive knowledge of psychopathology, personality, psychological measurement, research methods, assessment methods, and skill to integrate information with complex history, situational context, and developmental information.

The Standards for Educational and Psychological Testing in the 1999 edition suggests test publishers use competency-based qualification guidelines in determining who can purchase and administer various tests. This is to assure the ethical test use and appropriate interpretation of test results. Tests are usually assigned to one of several qualification levels. Psychological Assessment Resources, Inc. uses the following qualification guidelines. Qualification level A indicates no special qualifications are required. Qualification level B indicates a degree from an accredited 4-year college in psychology or related field plus satisfactory completion of course-work in testing. Qualification C indicates all qualifications for Level B plus an advanced professional degree that provides appropriate training in the administration and interpretation of psychological tests or a license or certification from an agency that requires training and experience in ethical and competent use of psychological tests. Finally, there is Qualification level S that requires a degree or license to practice in a health care profession or occupation including the following: medicine, neurology, nursing, occupational therapy, and other allied health care professions, physicians’ assistants, psychiatry, social work, speech and language pathology, plus appropriate training and experience in the ethical administration, scoring, and interpretation of clinical behavior assessment instruments. The first time a clinician purchases from a supplier, he/she is asked to supply supporting credentials.

There are numerous testing techniques utilized in the assessment of children and youth. These numerous tests can be divided into categories based on domains measured, the approach or method of measurement (e.g., individual, group, questionnaire, observation, and so on), or types of testing based on content. For example, Van Ornum et al. in their 2008 test suggest categorizing tests using a seven approaches model while the Standards for Educational and Psychological Testing in the 1999 text utilizes a categorization of tests based on domains measured. The classification of tests utilized here generally follows a model focusing on the
psychological domain measured, but under the domain of personality there is a subcatego-rization based on the method of measurement. The various tests illustrated here that are the most likely utilized in a good assessment include: achievement, behavioral problems, adaptive behavior, intelligence, personality—self-report, personality—projective, neuropsychological, and parenting/family.

The purpose of achievement testing is to measure an individual’s development, strengths and weaknesses in various areas of learning such as written expression, reading, spelling, math, nonverbal reasoning, language skills, expressive and receptive vocabulary, and so on. Often a child has behavioral problems in school or with peers due to learning and processing problems. These tests will help in identifying learning disabilities and deficits in learning various academic content areas requiring special focus.

The purpose of behavioral problem ratings is to get a concrete description of behavioral functioning across various living environments or settings such as school, home, day care, restaurants, and so on. Scales with a broad sampling of behavioral items are more useful than narrow samples. Also, scales that elicit ratings from various individuals in the client’s life (such as teacher, parent, friend, sibling, or self) are more useful than single rater forms. Ratings on various items are often combined into different scales such as aggression, level of isolation, externalizing behavior, internalizing behavior, and so on. These are most useful in helping to determine which behaviors are most excessive, the environments in which the behavior is most excessive, and whether the behavior is excessive for age.

Adaptive behavior techniques usually consist of other rating or semi-structured interview formats aimed at measuring a patient’s adaptive behavior or functional skills. These are skills considered important for personal responsibility, self-care, daily living, social functioning, and/or independent living. This type of measurement is required in assessing for developmental disabilities.

Intelligence testing measures the performance of a number of different tasks. These tasks represent certain abilities including the ability to learn or understand from experience, the ability to retain knowledge, reasoning ability, the ability to respond to new situations, and ability to direct behavior. These abilities are measured through the performance of verbal tasks and nonverbal tasks. These measures are often used in school settings to help determine placement, handicapping conditions, or appropriate modalities of treatment. For example, a child with low verbal skills would not do well in a high verbal reasoning type of therapy.

Personality tests measure the way in which a person may habitually or typically respond emotionally, cognitively, and behaviorally in various situations. This type of test often measures various manifest symptoms but also coping mechanisms, defenses, affect, perception of reality, thinking processes, ego functioning, conflicts, drives, motivators, level of distress, and so on. This category is broken into two types or methods of measurement, self-report and projective. Self-report usually entails having the client respond to a number of statements and indicating whether they are true or false. Projective tests involve the presentation of an ambiguous stimulus to a client in order to measure how his or her personality influences the way in which he/she perceives, organizes, and interprets his or her environment and experiences. These tests are often used to assist in differential diagnosis, treatment planning, and risk assessment.

Neuropsychological testing is concerned with the measurement of brain—behavior relations. In general, neuropsychological testing measures the human adaptive function dependent on the organic integrity of the brain. Consequently, there is a need to systematically measure most major adaptive behavior functions. Thus, neuropsychological assessment examines areas of learning, information processing, planning, sensory-motor functioning, perceptions, memory, executive functioning, attention, and personality changes. Neuropsychological testing is most useful when damage to the brain is suspected to be interfering with performance and adaptive functioning.

Parent/family types of tests are used to describe parent—child relationships, describe family functioning, identify stressful areas of parent—child interactions, identify strength of child rearing alliance between parents, or identify parenting skills. This is most useful in helping identify contextual issues affecting a child/youth’s symptom presentation.

Examples of tests commonly used by psychologists for the assessment of childhood or adolescent disorders are listed in Table 2-2 by type of test, appropriate age ranges to take the test, and where the test can be purchased.