PHQ-9 Calculator — Depression Screening After Stroke
Score the PHQ-9 in under a minute, read the severity band, and see why systematic screening matters after stroke — where depression affects roughly one in three survivors and is routinely missed.
Reviewed by Zaka Ahmed, MD Clinical reference · 4 min read
PHQ-9
"Over the last 2 weeks, how often have you been bothered by any of the following problems?" Score each item: Not at all (0) · Several days (+1) · More than half the days (+2) · Nearly every day (+3).
0 of 9 items complete
Score every item to see the severity band and suggested next step.
Educational tool only. The PHQ-9 is a screen, not a diagnosis: a positive screen calls for clinical interview (and in stroke patients, attention to aphasia, apathy, and pseudobulbar affect as confounders). It does not replace clinical judgment or in-person evaluation.
Clinical notes & interpretation Scoring guidance, pitfalls, FAQs, and references
Post-stroke depression is common, consequential, and missed
Roughly a third of stroke survivors develop depression, with the highest incidence in the first year. It is independently associated with worse functional recovery, poorer participation in rehab, higher caregiver strain, and higher mortality — and it is underdiagnosed, partly because fatigue, flat affect, and psychomotor slowing are easy to attribute to the stroke itself. That is the argument for a structured screen at defined points (before discharge, at the first clinic follow-up, and at 3 months) rather than relying on impression.
Interpreting the score in a stroke population
Three stroke-specific caveats. First, somatic items (sleep, energy, appetite, psychomotor change) can be elevated by the stroke and by hospitalization, inflating scores slightly — the trend across visits is more informative than a single number. Second, aphasia limits self-report instruments; for patients with significant language impairment use an observational scale (such as an aphasic-depression rating scale) or structured caregiver input instead of forcing a PHQ-9. Third, distinguish depression from post-stroke apathy (reduced initiation without low mood or anhedonia-related distress) and from pseudobulbar affect (involuntary crying spells without sustained low mood) — the treatments differ.
What a positive screen changes
A score of 10 or more warrants a diagnostic conversation, not reflex prescribing. When treatment is indicated, SSRIs are the usual first line after ischemic stroke; be deliberate about bleeding risk when combined with antithrombotics (SSRIs modestly increase bleeding, most relevant with anticoagulation or recent ICH) and about interactions. Psychotherapy and structured exercise carry meaningful evidence. Item 9 is a safety item, not a severity item — any positive response gets addressed the same visit.
Frequently asked questions.
What PHQ-9 score indicates depression?
Ten or more is the standard screening threshold for major depression (≈88% sensitivity and specificity in the original validation). Severity bands: 0–4 minimal, 5–9 mild, 10–14 moderate, 15–19 moderately severe, 20–27 severe. The score screens — diagnosis still requires clinical interview.
When should stroke patients be screened?
A pragmatic schedule: before discharge, at the first outpatient follow-up, and again around 3 months — incidence peaks within the first year, so a single normal inpatient screen is not the end of the question.
Can the PHQ-9 be used in aphasia?
Not reliably, once language impairment is more than mild. Use observational instruments or structured caregiver report; do not interpret a low score obtained through impaired comprehension as reassurance.
What about the PHQ-2?
The first two items (interest/pleasure and mood) work as an ultra-brief pre-screen: a PHQ-2 of 3 or more should trigger the full PHQ-9. In a stroke clinic where minutes matter, PHQ-2 for everyone and PHQ-9 for positives is a defensible workflow.
References.
- Kroenke K, Spitzer RL, Williams JB. The PHQ-9: validity of a brief depression severity measure. J Gen Intern Med. 2001;16(9):606–613. PubMed
- Towfighi A, Ovbiagele B, El Husseini N, et al. Poststroke depression: a scientific statement for healthcare professionals from the American Heart Association/American Stroke Association. Stroke. 2017;48(2):e30–e43. PubMed
- Hackett ML, Pickles K. Part I: frequency of depression after stroke: an updated systematic review and meta-analysis of observational studies. Int J Stroke. 2014;9(8):1017–1025. PubMed