CMP Psiquiatría common mistakes
CMP Psiquiatría · Understand the traps and how to avoid them.
Choosing the 'most severe-sounding' diagnosis when the vignette describes a time course that does not meet that disorder's duration criterion (e.g., calling a 5-day episode mania, or a 10-day psychosis schizophrenia).
Candidates pattern-match on the most dramatic symptom (grandiosity, hallucinations) and skip the timeline embedded in the stem, which is usually the discriminating detail.
What to do instead
Before answering any diagnostic question, write the symptom duration and functional impact on scratch paper and check it against the required threshold (mania 1 week or hospitalization; schizophrenia 6 months total with 1 month active; brief psychotic disorder 1 day–1 month; schizophreniform 1–6 months).
Confusing delirium with dementia and picking dementia as the answer for an acutely fluctuating, inattentive elderly patient with a new change in mental status.
Both present with cognitive impairment in older adults; candidates anchor on age and 'memory problems' and overlook the acute onset, fluctuating course, and attentional deficit that define delirium.
What to do instead
Apply the four delirium features as a checklist (acute onset, fluctuating course, inattention, disorganized thinking or altered consciousness); if present, delirium outranks dementia and the next step is to search for a medical cause, not start an antipsychotic or cholinesterase inhibitor.
Missing or mishandling the medical/medication cause of psychiatric symptoms, treating new psychosis or depression as primary when the stem includes a new drug, withdrawal, or abnormal vitals/labs.
Candidates stay in a psychiatric frame and underweight the physical findings, which are deliberately planted to make the diagnosis secondary to a general medical condition or substance.
What to do instead
Scan every vignette for a 'red flag list' (new medication, substance use, fever, tachycardia, hypertension, focal neuro signs, recent illness) before committing to a primary psychiatric diagnosis; if present, choose the medical/substance-induced option and the appropriate medical workup.
Selecting a first-line antidepressant at the wrong dose or timing, or switching too early, when the question tests adequate trial and expected latency.
Candidates know drug names but not the 4–6 week response window and adequate-dose concept, so they pick 'switch drug' or 'augment' at week 2 without dose optimization.
What to do instead
Memorize the rule: adequate trial = adequate dose for 4–6 weeks with adherence confirmed; at 2 weeks without response, optimize dose and reassess, do not switch; reserve augmentation/switch for true non-response after an adequate trial.
Confusing serotonin syndrome with neuroleptic malignant syndrome and choosing the wrong management (e.g., dantrolene for serotonin syndrome or cyproheptadine for NMS).
Both cause altered mental status, autonomic instability, and hyperthermia; candidates remember 'hyperthermia plus rigidity' but not the clonus/hyperreflexia versus lead-pipe rigidity and bradyreflexia distinction.
What to do instead
Use the discriminator: serotonin syndrome = clonus, hyperreflexia, mydriasis, GI symptoms, rapid onset after serotonergic agents, treat by stopping agent plus cyproheptadine/benzodiazepines; NMS = lead-pipe rigidity, bradyreflexia, CK elevation, days after antipsychotic, treat by stopping agent plus dantrolene/bromocriptine.
Endorsing a personality disorder diagnosis from a single cross-sectional encounter or during an acute mood/psychotic episode, rather than recognizing enduring, pervasive, stable patterns.
Vignettes show dramatic behavior (self-harm, anger, idealization) and candidates label the cluster without checking that the pattern is longstanding, inflexible, and present across contexts and not better explained by an Axis I episode.
What to do instead
Require evidence of early-onset, enduring, cross-situational pattern before choosing a personality disorder; if the stem describes an acute episode or recent change, prefer the mood/psychotic/substance explanation and note personality traits as a secondary consideration.
Failing to assess and act on suicide risk when the vignette contains indirect hints (recent loss, giving away possessions, hopelessness, access to means), instead focusing only on the named diagnosis.
Candidates treat suicide risk as a separate topic rather than an integrated step, so they answer the diagnostic question and ignore the safety question embedded in the stem.
What to do instead
For every clinical vignette, run a fixed safety screen (ideation, plan, intent, means, protective factors, prior attempts); if risk factors are present, the correct next step is direct risk assessment and safety planning, and the disposition (inpatient vs outpatient) follows risk, not diagnosis alone.
Misapplying capacity versus competence and involuntary-commitment criteria, choosing 'patient refuses, so respect autonomy' when the patient lacks decision-making capacity and poses danger.
Candidates conflate ethical principles (autonomy) with legal standards and do not separate clinical capacity assessment from the legal determination of competence and civil commitment criteria.
What to do instead
Separate the steps: assess capacity (understand, appreciate, reason, express choice); capacity is clinical, competence is legal; involuntary hold requires mental illness plus danger to self/others or grave disability; document the reasoning and choose the least restrictive option that meets criteria.
Overlooking a substance use disorder or withdrawal as the primary explanation when the stem describes intoxication/withdrawal physiology (e.g., tremor, seizures, autonomic hyperactivity) alongside psychiatric symptoms.
Candidates attribute symptoms to the psychiatric label already in the stem and do not consider that the presentation is substance-induced or in withdrawal, which changes both diagnosis and management.
What to do instead
Always ask 'could a substance explain this?' and match the syndrome to the substance and timeline (alcohol withdrawal 6–48 h with tremor/seizures/DTs; opioid withdrawal with piloerection/diarrhea/mydriasis; stimulant intoxication with tachycardia/paranoia); treat withdrawal per protocol (e.g., benzodiazepines for alcohol, not antipsychotics alone).
Mixing up psychotherapy indications and choosing an exposure-based or insight-oriented therapy for a condition where it is contraindicated or not first-line, or choosing medication when the question tests first-line psychotherapy.
Candidates memorize therapy names without matching them to disorder, acuity, and patient factors; they also forget that some disorders (e.g., OCD, panic, specific phobia, mild-moderate depression) have psychotherapy as a first-line equivalent or preferred option.
What to do instead
Build a disorder-to-first-line-treatment table (CBT/ERP for OCD and anxiety disorders; CBT or IPT or antidepressants for depression; DBT for borderline; exposure for phobias; supportive therapy and caution with insight-oriented work in acute psychosis); check severity and patient preference before defaulting to medication.