| Course | NU 671 Clinical Decision-Making in Psychiatric Mental Health |
|---|---|
| Unit | Unit 3 |
| Paper type | Diagnostic weighting table |
| Length | About 870 words, 6 pages |
| Format | APA 7 student paper |
| School | Herzing University |
| Program | MSN Psychiatric Mental Health Nurse Practitioner |
| Updated | October 2026 |
Free sample paper for NU 671 Unit 3
Diagnostic Weighting Table for Mr. K.: Ten Findings Against Six Candidate Explanations for Apathy, Fatigue, and Low Mood at 56
Student Name
Department of Nursing, Herzing University
NU 671: Clinical Decision-Making in Psychiatric Mental Health
Instructor Name
February 5, 2026
Diagnostic Weighting Table for Mr. K.: Ten Findings Against Six Candidate Explanations for Apathy, Fatigue, and Low Mood at 56
Purpose
Mr. K., the composite 56-year-old patient seen at intake, was referred with a diagnosis of depression that has not responded to sertraline. The interview and mental status examination produced findings that fit more than one explanation. Rather than argue toward the referral diagnosis, this table records each finding and states, for each candidate condition, whether the finding makes it more likely, less likely, or neither. Recording the direction for every candidate protects against anchoring on the first diagnosis offered, one of the cognitive errors most often implicated in diagnostic mistakes (Croskerry, 2003). The table uses only findings available before laboratory, sleep, and cognitive testing; those results will update it.
The Candidates
Six candidates were weighed: major depressive disorder; obstructive sleep apnea; an alcohol-related contribution; early neurocognitive disorder, including Alzheimer disease and frontotemporal degeneration; hypothyroidism; and a medication effect, from metoprolol or sertraline itself. They are not mutually exclusive, and more than one may be contributing.
The Table
Each cell states the direction in which the finding moves that candidate: raises, lowers, or neutral.
| Finding (as recorded) | Major depression | Sleep apnea | Alcohol | Early neurocognitive disorder | Hypothyroidism | Medication effect |
|---|---|---|---|---|---|---|
| Apathy noticed by wife before sadness | Lowers slightly | Raises | Neutral | Raises | Raises | Neutral |
| Unrefreshing sleep, daytime naps, falls asleep in chair | Neutral | Raises strongly | Raises | Neutral | Raises | Raises slightly |
| Loud snoring with witnessed pauses in breathing | Neutral | Raises strongly | Raises slightly | Neutral | Neutral | Neutral |
| Weight gain of about 20 pounds over two years | Neutral | Raises | Raises slightly | Neutral | Raises | Neutral |
| First episode at 56, no prior mood history | Lowers slightly | Neutral | Neutral | Raises | Raises slightly | Neutral |
| Recall one of three words, improved to three with cues | Raises | Raises | Neutral | Lowers for Alzheimer disease | Neutral | Neutral |
| Flat affect, passive death wishes | Raises | Neutral | Neutral | Neutral | Neutral | Neutral |
| Mother with dementia starting in her sixties | Neutral | Neutral | Neutral | Raises slightly | Neutral | Neutral |
| About 16 alcoholic drinks a week | Raises slightly | Raises | Raises | Neutral | Neutral | Neutral |
| No response after four months of sertraline at adequate dose | Lowers slightly | Raises | Raises | Raises | Raises | Neutral |
Reading Across the Rows
Several findings that were attributed to depression in the referral fit other explanations as well or better. Daytime sleepiness with unrefreshing sleep, loud snoring, and witnessed breathing pauses point strongly toward obstructive sleep apnea, which is common in middle-aged men with weight gain and is often undiagnosed (Peppard et al., 2013). Breathing-related sleep disorders and depressive disorders frequently occur together in the general population (Ohayon, 2003), so apnea does not rule out depression; it may be causing some of the symptoms or keeping a real depression from responding.
The finding that most separates the candidates is the memory pattern. He recalled one of three words after five minutes but recovered the other two with a category cue. Impaired free recall that improves with cues suggests a problem retrieving information, which is typical of depression and of sleep deprivation, rather than failure to store it, which is typical of early Alzheimer disease. This finding lowers the likelihood of Alzheimer disease without excluding other neurocognitive disorders, and a structured cognitive screen will test it further.
The lack of response to sertraline raises every non-depressive candidate. An antidepressant at an adequate dose for four months would be expected to produce at least partial improvement in a primary depressive episode; its failure suggests either a different or additional cause, or depression maintained by something the antidepressant does not treat, such as untreated apnea or regular alcohol use.
Reading Down the Columns
Obstructive sleep apnea is raised by seven findings and lowered by none. Major depression is raised by three findings and lowered slightly by three. Early neurocognitive disorder is raised by several findings but lowered, for Alzheimer disease specifically, by the most discriminating one. Hypothyroidism is raised by findings that are nonspecific and is cheaply tested. Alcohol is raised by several findings and is likely a contributor whatever the primary diagnosis. A medication effect is weakly supported: metoprolol can cause fatigue, but it has been taken for eight years and the change began about a year ago.
How the Table Will Be Updated
The table is a working document. Each pending result will be added as a new row, and its direction for each candidate recorded before the next decision. A high score on the sleep apnea questionnaire would raise apnea further; a sleep study showing a high apnea-hypopnea index would confirm it, though it would not by itself remove depression from the table. A thyroid-stimulating hormone within the reference range would lower hypothyroidism nearly to exclusion. A cognitive screen showing impairment concentrated in attention and retrieval, with preserved recognition, would further support depression or sleep deprivation over a degenerative process, while impairment in orientation and cued recall would raise neurocognitive disorder. An alcohol screen confirming hazardous drinking would keep alcohol as a contributor regardless of the other results.
Two findings could reverse the table's current direction and are named in advance. If the sleep study is normal, the case for apnea collapses and depression, perhaps with an alcohol contribution, becomes the leading explanation, with a medication change the next step. If his wife's account describes personality change, disinhibition, or loss of social awareness, frontotemporal degeneration would need specific evaluation despite his cued recall. Stating these reversals now makes it harder to explain away a result that does not fit.
What the Table Changes
The referral diagnosis of depression is not discarded; the flat affect, passive death wishes, and loss of interest support it. But the table changes the order of the next steps. Sleep apnea moves to the top of the list for testing, with a validated screening questionnaire and referral for a sleep study. Blood tests for thyroid, B12, glucose, liver, and kidney function are ordered, since they are inexpensive and each could change management. A structured alcohol screen and a cognitive screening instrument are completed. Increasing the sertraline dose, which the referral suggested, is deferred until these results return, because raising the dose of a medication that has not worked would treat the diagnosis the table has made less certain.
References
Croskerry, P. (2003). The importance of cognitive errors in diagnosis and strategies to minimize them. Academic Medicine, 78(8), 775-780. https://doi.org/10.1097/00001888-200308000-00003
Ohayon, M. M. (2003). The effects of breathing-related sleep disorders on mood disturbances in the general population. The Journal of Clinical Psychiatry, 64(10), 1195-1200. https://doi.org/10.4088/JCP.v64n1009
Peppard, P. E., Young, T., Barnet, J. H., Palta, M., Hagen, E. W., & Hla, K. M. (2013). Increased prevalence of sleep-disordered breathing in adults. American Journal of Epidemiology, 177(9), 1006-1014. https://doi.org/10.1093/aje/kws342
Reading the NU 671 Unit 3 instructions
Unit 3 asks you to build a differential diagnosis for a psychiatric presentation and weigh each candidate against the findings. Expect to list candidate diagnoses, including medical and substance-related ones, set out key findings, judge how each finding bears on each candidate and draw conclusions about what to test next. Many versions use a table. Check how many candidates your section expects; five or six is common. Include substance use and medical conditions as candidates, not afterthoughts. Each cell should state a direction, raises, lowers or neutral, rather than a guess at probability. The table is a working tool, so explain how results will be added. Watch for anchoring on the referral diagnosis, which is the cognitive error this exercise is built to counter.
How this NU 671 Unit 3 example is built
The paper opens with the purpose: to test the referral diagnosis against alternatives. Candidates are listed with a sentence on why each is plausible. The table is the core, with findings in rows and candidates in columns. Two reading sections follow. Across the rows, the paper shows that sleepiness, snoring and morning headaches fit sleep apnea at least as well as depression. Down the columns, it counts how many findings raise or lower each candidate. The updating section explains how pending sleep study and laboratory results will become new rows. The final section is balanced, keeping depression in the differential while showing the table points to testing for sleep apnea and reducing alcohol before escalating antidepressant treatment.
Where the points sit in the NU 671 Unit 3 rubric
Herzing's rubric for a diagnostic weighting exercise usually covers the range of candidates, the selection of findings, the accuracy of weighting, the analysis, next steps and writing. Candidate range points reward medical and substance-related explanations alongside psychiatric ones. The weighting is checked cell by cell, so each direction should be defensible from the evidence. Analysis criteria look for conclusions drawn both across findings and down candidates. Next step points go to tests that would separate the leading candidates. Awareness of anchoring bias may be credited within analysis. A readable table matters. Croskerry and the Wisconsin sleep cohort by Peppard belong in the APA 7 list.
Common NU 671 Unit 3 mistakes, and how to avoid them
Weighting tables in Unit 3 commonly lose points by listing only psychiatric diagnoses. Another frequent problem is cells marked with unexplained probabilities. Students often weight every finding toward the referral diagnosis, which repeats the anchoring the exercise is meant to expose. Findings are selected to fit a favored diagnosis. Analysis restates the table. Next steps are generic, such as further evaluation. Finally, keep the referral diagnosis in play while testing alternatives, because graders reward balanced reasoning rather than a table that simply swaps one confident diagnosis for another. Pending tests are sometimes left out of the table, so it cannot be updated when results arrive. Each candidate should also have at least one finding that could lower it; a column with only raises suggests the findings were chosen to fit.
Get a NU 671 Unit 3 example written to your instructions
Send the Unit 3 instructions and the rubric from your NU 671 classroom, with the presentation the table should work from. We write a custom example with candidates assembled before any weighing, rows kept in the order gathered, every cell given a direction, absent findings included, and the overturning evidence named. First custom sample free, delivered inside 24 to 48 hours.
More NU 671 papers and PMHNP samples
- NU 671 Unit 1: Annotated intake interview
- NU 671 Unit 2: Mental status examination record
- NU 671 Unit 4: Medical mimic exclusion log
- NU 671 Unit 5: Diagnostic criteria mapping
- NU 671 Unit 6: Rating instrument administration note
- NU 671 Unit 7: Collateral information summary
- NU 671 Unit 8: Biopsychosocial formulation
- NU 672 Unit 3: Session transcript analysis
- NU 673 Unit 3: Psychoeducation session outline
- NU 674 Unit 3: Comorbidity sequencing plan
- NU 670 Unit 3: Whole regimen interaction screen
NU 671 Unit 3 questions, answered
How many candidates belong in the differential?
Enough to hold whatever could plausibly explain the picture, which usually means three to five conditions plus the medical and substance-related possibilities kept as a standing category. A list of ten is unmanageable and mostly padding. Range matters more than count, since candidates drawn from one family cannot be separated by findings all of them share.
Should substance use appear as a candidate?
Almost always, and as rows of findings rather than an afterthought at the end. Intoxication, withdrawal and sustained use produce presentations overlapping most psychiatric conditions, and the timing questions separating them belong inside the grid. The same holds for prescribed agents, which is why the medication list sits among the findings rather than in a footnote.
Does every cell need to be filled?
Filling every cell is what makes the table honest, since blanks hide the findings that fail to discriminate. Where a finding says nothing about a candidate, record that verdict rather than leaving a gap a reader will read as an oversight. The pattern of non-discriminating cells is frequently the most informative thing a completed grid shows.
Where can I find a free NU 671 Unit 3 sample paper?
This page shows the whole NU 671 Unit 3 weighting table for free, ten findings against six candidates with both readings explained. A table for a different presentation, such as new psychosis in an older adult, can be built on request.
Can sleep apnea look like depression?
Yes. Fatigue, poor concentration, low motivation and irritability are common to both. In this sample, snoring, morning headaches and falling asleep during the interview raise obstructive sleep apnea as strongly as depression.