Diagnosis and Treatment Planning
What this domain tests
DSM-5-TR criteria recognition, differential diagnosis, and translating a diagnosis into a measurable, collaborative treatment plan.
Core rules
- DSM-5-TR (2022) uses a nonaxial format of criteria, specifiers, and severity, with Z codes for psychosocial stressors and the Cultural Formulation Interview for cultural context. ACA E.5.b requires cultural sensitivity in diagnosis.
- Major depressive disorder: at least 5 symptoms for 2 weeks, and one must be depressed mood or anhedonia. Persistent depressive disorder: 2 years in adults, 1 year in youth. GAD: 6 months of excessive worry plus 3 of 6 symptoms. Panic attacks are a specifier applicable across disorders.
- PTSD (4 clusters: intrusion, avoidance, negative cognitions/mood, hyperarousal) lasting over 1 month; acute stress disorder runs 3 days to 1 month. Obsessive-compulsive disorder is its own chapter, separate from anxiety.
- Schizophrenia: 2 or more symptoms for at least 6 months with 1 month active, and at least one must be delusions, hallucinations, or disorganized speech. Personality disorders: Cluster A (paranoid, schizoid, schizotypal), B (antisocial, borderline, histrionic, narcissistic), C (avoidant, dependent, obsessive-compulsive). Substance use disorder: 11 criteria; 2-3 mild, 4-5 moderate, 6+ severe.
- Treatment plans link problem, measurable goal, objective, intervention, timeline, and review to the diagnosis, built with the client.
Worked example
A client reports 3 weeks of low mood, anhedonia, insomnia, poor concentration, guilt, and weight loss; no mania, no substance use, and a death in the family 3 months ago. Reasoning: 5+ symptoms for 2 weeks with the two required symptoms supports MDD, single episode; rule out medical and substance causes; note that the bereavement exclusion is gone but prolonged grief disorder is a separate diagnosis. Plan behavioral activation and CBT, track PHQ-9, and re-evaluate.
Traps that cost marks
- Diagnosing in one session without ruling out medical or substance causes.
- Confusing bipolar II with cyclothymia.
- Pathologizing culturally normative behavior.
- Writing goals that are not measurable or not linked to the diagnosis.