Clinical Assessment and Diagnosis
What you must know
Clinical assessment is the process of gathering, integrating, and interpreting information about a client; diagnosis is the formal classification of that information. Know the difference between reliability (consistency), validity (accuracy), and standardization (uniform administration and norms). Understand the purposes of assessment: screening, diagnosis, treatment planning, and outcome monitoring. Learn the major instrument families - intelligence tests, achievement tests, personality inventories (objective vs. projective), symptom checklists, neuropsychological batteries, and behavioral observation - and the strengths and limits of each. Familiarity with the DSM's multiaxial history and current criteria-based approach, differential diagnosis, and cultural formulation matters.
Traps in questions
- Confusing reliability with validity. A test can be reliably wrong. A scale that reads five pounds heavy every time is reliable but not valid.
- Confusing test-retest with inter-rater reliability. Test-retest is stability over time; inter-rater is agreement between scorers.
- Overreading projective instruments. Questions often expect you to recognize them as hypothesis-generating, not definitive.
- Ignoring base rates and cultural bias. A rare condition yields many false positives even with a good test.
- Diagnosis vs. assessment. Assessment is continuous and hypothesis-driven; diagnosis is a snapshot at a point in time.
Worked rule of thumb
When a stem describes a client whose symptoms overlap several categories, look for the criterion that best explains the onset, duration, and functional impairment rather than the most dramatic symptom. If a test's manual reports high internal consistency but low correlation with clinician ratings, the correct answer usually flags limited validity evidence. Remember: assess broadly, diagnose cautiously, and always consider culture, context, and base rates.