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Does the risk of developing dementia increase with the number of episodes in patients with depressive disorder and in patients with bipolar disorder?
Kessing LV, Andersen PK.. Journal of neurology, neurosurgery, and psychiatry, 2004-12-01
Topic: Risk, prevention and care in population studies
Objective Several findings suggest that some patients with depressive or bipolar disorder may be at increased risk of developing dementia. The present study aimed to investigate whether the risk of developing dementia increases with the number of affective episodes in patients with depressive disorder and in patients with bipolar disorder. Methods This was a case register study including all hospital admissions with primary affective disorder in Denmark during 1970-99. The effect of the number of prior episodes leading to admission on the rate of readmission with a diagnosis of dementia following the first discharge after 1985 was estimated. A total of 18,726 patients with depressive disorder and 4248 patients with bipolar disorder were included in the study. Results The rate of a diagnosis of dementia on readmission was significantly related to the number of prior affective episodes leading to admission. On average, the rate of dementia tended to increase 13% with every episode leading to admission for patients with depressive disorder and 6% with every episode leading to admission for patients with bipolar disorder, when adjusted for differences in age and sex. Conclusion On average, the risk of dementia seems to increase with the number of episodes in depressive and bipolar affective disorders.
Cite this study APA, Vancouver, BibTeX · download .bib or .ris
APA 7th
Kessing, L. V., & Andersen, P. K. (2004). Does the risk of developing dementia increase with the number of episodes in patients with depressive disorder and in patients with bipolar disorder? Journal of neurology, neurosurgery, and psychiatry. https://doi.org/10.1136/jnnp.2003.031773
Vancouver
Kessing LV, Andersen PK. Does the risk of developing dementia increase with the number of episodes in patients with depressive disorder and in patients with bipolar disorder? Journal of neurology, neurosurgery, and psychiatry. 2004. doi:10.1136/jnnp.2003.031773. PMID: 15548477.
BibTeX
@article{kessing2004-15548477,
author = {Kessing, L. V. and Andersen, P. K.},
title = {{Does the risk of developing dementia increase with the number of episodes in patients with depressive disorder and in patients with bipolar disorder?}},
journal = {Journal of neurology, neurosurgery, and psychiatry},
year = {2004},
doi = {10.1136/jnnp.2003.031773},
pmid = {15548477},
url = {https://doi.org/10.1136/jnnp.2003.031773}
}
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Key findings
- Objective Several findings suggest that some patients with depressive or bipolar disorder may be at increased risk of developing dementia.
- Results The rate of a diagnosis of dementia on readmission was significantly related to the number of prior affective episodes leading to admission.
Why it matters
In a Danish register study of 18,726 people with depressive disorder and 4,248 with bipolar disorder, the rate of a dementia diagnosis on readmission rose with each prior episode leading to admission. This is an observational link between mood disorder episodes and later dementia, not evidence that treating or preventing those episodes prevents Alzheimer's disease.
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Study details
- Participants18,726
- Evidence strengthLow
How this study scored 52/100
Published in a peer-reviewed journal. Scored zero for study design, effect reported and randomised / blinded because the record does not state it.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (Journal of neurology, neurosurgery, and psychiatry) |
| Journal's citation record | 3 / 4 | Journal of Neurology Neurosurgery & Psychiatry: journal h-index 336 (OpenAlex, 2026-10-29) |
| Study design | 0 / 12 | No study design recorded — scores zero, not guessed (not stated in the record — scored 0) |
| Strength of evidence | 1 / 5 | Rated “low” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 1 / 5 | 2004 — older than 20 years, still counted |
| Sample size | 4 / 4 | 18,726 participants |
| Effect reported | 0 / 3 | No effect size reported — scores zero (not stated in the record — scored 0) |
| Studied in people | 3 / 3 | Studied in people (participant count stated) |
| Randomised / blinded | 0 / 2 | No randomisation or blinding stated — scores zero (not stated in the record — scored 0) |
| Times cited | 6 / 7 | Cited 408 times (OpenAlex, 2026-10-10) |
| Citations per year | 3 / 5 | 17.0 citations a year over 24 year(s) since 2004 |
| Impact for its field and year | 3 / 6 | Cited 7.8× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 2 / 6 | Cited by 9 other studies in this library |
| Still being cited | 2 / 4 | Cited 48 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 3 / 4 | Last-listed author Lars Vedel Kessing: h-index 96 (OpenAlex, whole career) |
| Institution's track record | 1 / 3 | Rigshospitalet: institution h-index 882 (OpenAlex) |
| Multi-centre collaboration | 1 / 3 | OpenAlex lists 2 institution(s) in 1 country |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 15548477) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Total | 52 / 100 | — |
What each of these 20 components measures, and what this score is not →
Read the original
- DOI: 10.1136/jnnp.2003.031773
- PubMed: 15548477
- Original source →
- Free full text: Journal of Neurology Neurosurgery & Psychiatry →
Full text: free to read — OpenAlex lists this copy as free to read: the link above (checked 6 Feb 1020).
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