NursingCase studyMental health nursing

Assessing and treating an adult mood disorder

The assignment states the three tests up front — severity, functional impact and duration — and a diagnosis that satisfies only one of them is the commonest failure in this case.

Aug 15, 2026

Editorial process

Last reviewed · August 15, 2026

Written by

Aaron Bishop

MA, Education

assignment interpretation and research-methods coaching across disciplines

Reviewed by

Dr. Nathan Cole

PhD, Rhetoric & Composition

Argumentation and thesis development

On this page

Interpret the task
Assignment instructions
Deliverables
Proposed outline
Research plan
Reference shortlist
Final review

Diagnosis has three tests, not one

The introduction hands you the diagnostic structure, so use it as your framework rather than reading past it: a mood disorder is diagnosed when the emotional state meets criteria for severity, functional impact and length of time. Address all three explicitly for your case patient, because low mood that is severe but two weeks old, or persistent but not impairing, does not meet the threshold, and saying which criterion your patient meets and how you know is what an assessment is. Build the assessment from what the case supplies: presenting symptoms with onset and duration, the functional consequences at work and in relationships, past episodes and their character, family history, substance use, medical contributors such as thyroid disease and medication effects, and a risk assessment that is documented rather than assumed. Say where each piece came from in the case, because an assessment that reads as a template has not shown you read the patient.

The differential is where a PMHNP-level answer separates itself, and one question dominates it: has there ever been a manic or hypomanic episode? A depressive presentation that is actually bipolar disorder will be made worse by an antidepressant given without a mood stabiliser, which is the most consequential error available here, so screen for it and say that you did. Then run the rest — persistent depressive disorder, adjustment disorder, substance-induced mood disorder, and grief where the loss is recent — saying for each what makes it more or less likely in this patient. The plan should be more than pharmacological only: the medication with a starting dose and a rationale for that agent in this patient, psychotherapy named by modality, safety planning if risk is present, lifestyle and psychoeducation, the follow-up interval, and what you would measure at that follow-up to know whether it is working. Name a scale rather than saying you would assess response.

Likely learning objectives

Inferred from the brief — check these against your own rubric.

01
Apply severity, functional impact and duration as three separate diagnostic tests.
02
Screen for a history of mania or hypomania before treating a depressive presentation.
03
Construct a differential in which each candidate is weighed against the case's features.
04
Devise a treatment plan with a measurable follow-up rather than a review appointment.

Assignment instructionsQuoted verbatim

Read the full question

Review every instruction before using the planning guidance that follows.

It is important for the PMHNP to have a comprehensive understanding of mood disorders in order to assess and accurately formulate a diagnosis and treatment plan for patients presenting with these disorders. Mood disorders may be diagnosed when a patient’s emotional state meets the diagnostic criteria for severity, functional impact, and length of time. Those with a mood disorder may find that their emotions interfere with work, relationships, or other parts of their lives that impact daily functioning. Mood disorders may also lead to substance abuse or suicidal thoughts or behaviors, and although they are not likely to go away on their own, they can be managed with an effective treatment plan and understanding of how to manage symptoms. In this Assignment you will assess, diagnose, and devise a treatment plan for a patient in a case study who is presenting with a mood disorder. To Prepare Review this week’s Learning Resources. Consider the insights they provide about assessing, diagnosing, and treating mood disorders. Review the Focused SOAP Note template, which you will use to complete this Assignment. There is also a Focused SOAP Note Exemplar provided as a guide for Assignment expectations. Review the video, Case Study: Petunia Park. You will use this case as the basis of this Assignment. In this video, a Walden faculty member is assessing a mock patient. The patient will be represented onscreen as an avatar. Consider what history would be necessary to collect from this patient. Consider what interview questions you would need to ask this patient. The Assignment Develop a Focused SOAP Note, including your differential diagnosis and critical-thinking process to formulate a primary diagnosis. Incorporate the following into your responses in the template: Subjective: What details did the patient provide regarding their chief complaint and symptomatology to derive your differential diagnosis? What is the duration and severity of their symptoms? How are their symptoms impacting their functioning in life? Objective: What observations did you make during the psychiatric assessment? Assessment: Discuss the patient’s mental status examination results. What were your differential diagnoses? Provide a minimum of three possible diagnoses with supporting evidence, listed in order from highest to lowest priority. Compare the DSM-5 diagnostic criteria for each differential diagnosis and explain what DSM-5 criteria rules out the differential diagnosis to find an accurate diagnosis. Explain the critical-thinking process that led you to the primary diagnosis you selected. Include pertinent positives and pertinent negatives for the specific patient case. Plan: What is your plan for psychotherapy? What is your plan for treatment and management, including alternative therapies? Include pharmacologic and nonpharmacologic treatments, alternative therapies, and follow-up parameters as well as a rationale for this treatment and management plan. Also incorporate one health promotion activity and one patient education strategy. Reflection notes: What would you do differently with this client if you could conduct the session again? Discuss what your next intervention would be if you were able to follow up with this patient. Also include in your reflection a discussion related to legal/ethical considerations (demonstrate critical thinking beyond confidentiality and consent for treatment!), health promotion, and disease prevention that takes into consideration patient factors (such as age, ethnic group, etc.), PMH, and other risk factors (e.g., socioeconomic, cultural background, etc.).

Turn the brief into deliverables

01
A structured assessment of the case patient.
02
An explicit statement of how each of the three diagnostic thresholds is met.
03
A differential with reasoning for and against each candidate.
04
A treatment plan covering pharmacology, psychotherapy, safety and psychoeducation.
05
A follow-up interval and a named outcome measure, with APA citations.

Assessment, differential, diagnosis, then the plan

Structured assessment

Gather symptoms, duration, function, history, substances and medical contributors.

The three thresholds

Show explicitly how severity, functional impact and duration are met.

Differential, starting with bipolarity

Screen for past mania, then weigh the remaining candidates.

The treatment plan

Give medication with rationale, psychotherapy modality, safety planning and education.

Follow-up and measurement

Set an interval and name the instrument you would use to judge response.

Sources for mood disorder diagnosis and treatment

Recommended databases

NCBI Bookshelf (StatPearls)
PubMed Central
Your week's Learning Resources
Professional psychiatric practice guidelines

Search sequence

1.
Read the diagnostic criteria directly rather than from a summary, since the three thresholds are the assignment's frame.
2.
Look up the evidence on antidepressant-induced switching, which justifies the bipolar screen.
3.
Check current first-line pharmacological choices, which change and are specific to presentation.
4.
Find a validated symptom measure for the follow-up section, and note its scoring.

Reference shortlist

These are authoritative starting points, not a ready-made bibliography. A qualified reviewer must confirm that each source fits the assignment and supports the claim beside which it is cited.

Nothing here is cleared for citation until you have read it.

01
Major Depressive Disorder
StatPearls, NCBI Bookshelf · 2023
Diagnostic criteria, differential and treatment for depressive presentations, which carries most of the case.
02
Bipolar Disorder
StatPearls, NCBI Bookshelf · 2023
The bipolar differential and why an antidepressant without a stabiliser is the consequential error.
03
Suicide Ideation Screening, Risk Assessment, and Lethal Means Counseling During Zero Suicide Implementation
Psychiatric Services · 2024
Screening, risk assessment and lethal means counselling, for the safety component of the plan.
04
Ethics and governance of artificial intelligence for health
World Health Organization · 2021
Service-level framing for follow-up and continuity, which the plan's final section depends on.

Review before submission

Common mistakes

Naming a diagnosis without showing that all three thresholds are met.
Failing to screen for past mania, which is the error with the worst consequence.
Listing differentials without weighing them against the case.
Producing a medication-only plan.
Saying you would assess response without naming an instrument.

Submission checklist

Have you addressed severity, functional impact and duration separately?
Did you document a screen for manic or hypomanic history?
Is each differential argued for and against?
Does the plan include therapy, safety and psychoeducation?
Is there a follow-up interval with a named measure?

Use this guide to plan and review your own work. Follow your institution's rules and read our academic-integrity policy.