The Politicized Practitioner
Differential Diagnosis Lab
Interactive cases for learning how to build, test, and document a
differential diagnosis—one symptom, decision tree, comparison table,
and provisional formulation at a time.
Start with the method.
These simulations do not ask you to guess a diagnosis. They ask you to
show how you ruled possibilities in, ruled them out, or retained them
as uncertain.
The seven-step trees-and-tables method
1
Broad rule-outs
2
Key symptoms
3
Tree matching
4
Tree walks
5
Candidate list
6
Table comparison
7
Provisional formulation
How to use each pair:
complete the A case first for guided coaching. Then complete the B
case with fewer prompts and compare your reasoning with the expert
debrief.
Related reading
Diagnosis has a history
Explore the history, power, and assumptions surrounding psychiatric diagnosis.
Depression and low mood
01A · Guided practice
Use lifetime course, activation, and safety information before
settling on unipolar depression.
Open simulation →
01B · Independent application
Differentiate grief-related experience, adjustment disorder, and
a depressive disorder without pathologizing attachment or
overlooking risk.
Open simulation →
Possible mania and mood instability
02A · Guided practice
Use chronology to distinguish intoxication or substance-induced
symptoms from a primary bipolar episode while responding to acute
risk.
Open simulation →
02B · Independent application
Distinguish sustained mood episodes from rapid, cue-linked
affective reactivity without reducing the person to a personality
label.
Open simulation →
Hearing voices, unusual beliefs, and psychosis
03A · Guided practice
Use the temporal relationship between psychosis and mood symptoms
to distinguish mood, schizoaffective, schizophrenia-spectrum,
substance, and medical explanations.
Open simulation →
03B · Independent application
Assess voice-hearing phenomenology, trauma, culture, function, and
risk without assuming that an unusual experience equals a
psychotic disorder.
Open simulation →
Anxiety and excessive worry
04A · Guided practice
Recognize panic phenomenology without using a psychiatric
explanation to bypass medical red flags.
Open simulation →
04B · Independent application
Differentiate generalized anxiety, social anxiety, obsessive
doubt, trauma-related vigilance, and realistic stress by
examining the object and function of worry.
Open simulation →
Intrusive thoughts
05A · Guided practice
Distinguish ego-dystonic obsessions from intent while conducting a
real safety assessment.
Open simulation →
05B · Independent application
Differentiate trauma intrusions from obsessions, rumination, and
psychosis through trigger, sensory quality, orientation, meaning,
and associated symptoms.
Open simulation →
Trauma-related symptoms
06A · Guided practice
Use timing and symptom pattern to distinguish acute stress
responses, acute stress disorder, PTSD, and other conditions
without minimizing distress.
Open simulation →
06B · Independent application
Differentiate prolonged grief, PTSD, depression, and culturally
situated mourning while allowing comorbidity.
Open simulation →
Attention and concentration problems
07A · Guided practice
Use developmental onset, cross-setting persistence, functional
history, mood, sleep, and substances to evaluate adult attention
complaints.
Open simulation →
07B · Independent application
Differentiate neurodevelopmental symptoms from trauma, anxiety,
learning needs, sleep problems, and context while avoiding
discipline-driven diagnosis.
Open simulation →
Emotional instability and relationship crises
08A · Guided practice
Compare episodic mood course with pervasive relational and
self-function patterns while avoiding diagnostic stigma.
Open simulation →
08B · Independent application
Distinguish enduring personality pathology from trauma
adaptation, realistic threat appraisal, institutional
inconsistency, and clinician-system dynamics.
Open simulation →
Dissociation and feeling unreal
09A · Guided practice
Distinguish depersonalization/derealization, panic, psychosis,
substance effects, and neurologic conditions.
Open simulation →
09B · Independent application
Keep dissociative disorders, seizures, sleep, substances, and
medical causes open while avoiding suggestive interviewing.
Open simulation →
Eating and food restriction
10A · Guided practice
Differentiate restriction driven by weight/shape concerns from
sensory sensitivity, feared consequences, low interest, and
medical causes.
Open simulation →
10B · Independent application
Identify binge episodes and compensatory behaviors without
relying on body size, gender, or vomiting stereotypes.
Open simulation →
Confusion and cognitive change
11A · Guided practice
Recognize acute fluctuating inattention as a medical emergency and
avoid attributing it to age or presumed dementia.
Open simulation →
11B · Independent application
Differentiate depression-related cognitive impairment from
neurocognitive disorder while avoiding the misleading assumption
that one excludes the other.
Open simulation →
Physical symptoms without clear explanation
12A · Guided practice
Understand that functional neurologic disorder is diagnosed
through positive clinical features, not merely normal tests or
presumed psychological conflict.
Open simulation →
12B · Independent application
Differentiate illness anxiety from somatic symptom disorder and
avoid equating either with “symptoms are imaginary.”
Open simulation →
Substance use and psychiatric symptoms
13A · Guided practice
Use exposure, abstinence course, prior symptoms, collateral, and
functional change without assuming that substance use settles the
diagnosis.
Open simulation →
13B · Independent application
Recognize alcohol withdrawal as a potentially life-threatening
medical condition rather than treating the presentation as
uncomplicated anxiety.
Open simulation →
Clinical boundary.
The lab is educational. Use current diagnostic criteria, supervision,
scope-of-practice requirements, medical evaluation, and local emergency
procedures in real practice.
Where to go next
Free screening questionnaires for attention, anxiety and mood, with guidance on using them in assessment.
Structured CE pathways in psychodynamic practice, supervision and anti-oppressive care.
Case consultation on assessment, formulation and using the DSM critically.