FASS common mistakes
FASS · Understand the traps and how to avoid them.
Selecting a diagnosis because the vignette's most vivid symptoms match a disorder's prototype, without checking that all required criteria are met and that competing diagnoses are excluded.
Candidates pattern-match on a few salient features (e.g., 'grandiosity' triggers mania) and stop evaluating once a candidate diagnosis feels familiar, skipping the differential and duration/course checks the item is testing.
What to do instead
Before selecting, explicitly run the criteria list for the top two or three candidate disorders, ticking each required criterion as present, absent, or unknown, and confirm the chosen diagnosis accounts for the full symptom picture rather than a subset.
Confusing measures by their labels and psychometric properties, choosing a test because it is well known rather than because its norms, validity, or construct match the referral question and population.
Candidates memorize instrument names and abbreviations but not the population on which each was normed or the construct it actually measures, so items about appropriate test selection or norm fit defeat them.
What to do instead
For each major instrument, build a one-line profile: construct measured, norming population, format, and key limitation; when answering, first state the referral question and population, then match the instrument whose norm group and construct align.
Treating a single elevated scale score or an actuarial cut score as a diagnosis or as a definitive risk determination without integrating collateral data, base rates, and clinical context.
Candidates over-rely on numbers because they seem objective, forgetting that scores are probabilistic and depend on base rates and the population tested.
What to do instead
For any score-based item, ask what the base rate is in this population and what the score changes about the prior probability; state that scores inform but do not replace integrated clinical judgment, and prefer answers that combine data sources.
Failing to apply the malingering versus factitious versus genuine-disorder distinction correctly, or labeling exaggeration of symptoms as malingering when the motive is not external.
Candidates conflate the presence of inconsistency or exaggeration with malingering, ignoring the requirement of an external incentive and the possibility of genuine disorder with superimposed exaggeration.
What to do instead
For each such item, explicitly identify the incentive (external gain vs. internal psychological need vs. none) and the evidence of intentional production, then map to malingering, factitious disorder, or genuine presentation accordingly.
Using unstructured clinical judgment alone to predict violence, or conversely treating an actuarial instrument as a complete substitute for structured professional judgment.
Candidates pick either the 'clinical judgment' or the 'actuarial' answer as a rule, rather than recognizing that structured professional judgment integrates validated risk factors with individualized formulation and management.
What to do instead
Anchor on the principle that risk assessment should be structured and evidence-based; favor answers that use validated risk factors plus individualized formulation, and reserve 'clinical judgment alone' for items explicitly about its weaknesses.
Ignoring base rates when interpreting risk instruments, or applying a high-risk label without considering the low base rate of violence in the population.
Candidates attend to sensitivity and the instrument's label but not to positive predictive value, which collapses when base rates are low, leading to overestimation of risk.
What to do instead
For any risk-instrument item, first ask the base rate in that setting; if it is low, note that even a good instrument yields many false positives, and choose answers reflecting cautious, management-focused conclusions.
Confusing the roles of the treating clinician and the forensic evaluator, or allowing a therapeutic alliance to contaminate a forensic opinion.
Candidates carry over therapeutic assumptions (empathy, advocacy, confidentiality) into forensic contexts where the evaluator's duty is to the court and objectivity is paramount.
What to do instead
Before answering any role item, state the role explicitly (treating vs. forensic) and the corresponding obligations; forensic answers should prioritize objectivity, informed consent about limited confidentiality, and multiple data sources.
Misapplying the Tarasoff duty, confidentiality limits, or privilege in a legal scenario by treating them as absolute or ignoring jurisdiction-specific variation.
Candidates memorize that 'confidentiality has exceptions' without knowing which exception applies, to whom the duty runs, and that statutes vary by jurisdiction.
What to do instead
For each ethics/legal item, name the specific duty or exception triggered by the facts (e.g., imminent danger to an identifiable victim, child abuse reporting, court order) and note that the answer should reflect the governing jurisdiction's law rather than a generalized rule.
Confusing the legal standards and burdens in criminal versus civil contexts, or conflating competency with criminal responsibility.
Candidates blur the distinct questions (can the defendant proceed vs. was the defendant responsible at the time) and their different standards and timing.
What to do instead
Build a comparison table: competency to stand trial (present ability, Dusky standard), criminal responsibility (mental state at the time of the offense), civil commitment (dangerousness and mental disorder), and for each item identify which question is being asked before selecting the standard.
Giving conclusory expert testimony that opines on the ultimate legal issue or exceeds the scope of the psychologist's expertise, or failing to distinguish facts from opinions in testimony.
Candidates want to give the 'helpful' definitive answer and forget that the fact-finder decides legal conclusions and that experts must stay within their competence and evidentiary rules.
What to do instead
In testimony items, prefer answers that offer data-based opinions, distinguish observation from inference, and defer ultimate legal conclusions to the court; check that the proffered opinion falls within the expert's training and the evidence admitted.