Oct 7, 2026·Special Population & Related Conditions
Lupus and IQ: Does Lupus Affect Intelligence and Thinking Skills?
Lupus IQ studies mostly find average full-scale scores, but many people with lupus show weaker attention, processing speed and memory on detailed testing.
Dr. Russell T. WarneChief Scientist
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Lupus does not usually lower IQ: in most studies, people with systemic lupus erythematosus (SLE) score in the average range on full-scale IQ tests. What lupus does often bring is weaker performance on specific skills such as attention, processing speed and memory, and estimates of how many people have measurable "cognitive dysfunction" range from under a quarter to over 80% depending on how it is defined.
This article covers what the research shows about lupus IQ scores, how common cognitive problems are in neuropsychiatric lupus, which thinking skills are most affected, and what seems to drive the differences over time. It describes research findings and does not give medical advice. Anyone with lupus who notices changes in memory or concentration should raise them with their rheumatologist, who can arrange an assessment by a neuropsychologist.
What IQ scores look like in lupus
When researchers give people with lupus a full intelligence test, the overall score is usually close to average. The differences show up on narrower tests.
• Adults compared with their own baseline: Skeel and colleagues compared current test scores of adults with SLE against reading scores, which estimate ability before the illness. They found the largest weaknesses in expressive language, attention and processing speed, and no impairment in measured intelligence.
• Adults compared with other patients: Kozora and colleagues tested 51 people with SLE and no history of central nervous system disease, 29 people with rheumatoid arthritis and 27 healthy controls. Both patient groups showed similar modest reductions in intelligence, attention and verbal fluency compared with controls, which suggests that part of the gap comes from living with a chronic illness and is not specific to lupus.
• Children and teenagers: In a New York study of 41 young people with childhood-onset SLE, the average full-scale IQ on the Wechsler Abbreviated Scale of Intelligence was 96.8, against 96.7 for matched healthy controls. A smaller South Carolina study of 24 children with SLE found a lower average of 87.9, compared with 105.3 in children with juvenile idiopathic arthritis, a different rheumatic disease.
The childhood results show why single studies need caution. Samples are small, comparison groups differ, and a two-subtest screening IQ carries more measurement error than a full battery. Taken together, the evidence points to IQ scores that sit in or near the average range for most people with lupus, with a wide spread around that average.
Neuropsychiatric lupus and how common cognitive problems are
Lupus is an autoimmune disease, meaning the immune system attacks the body's own tissues. When it affects the brain or nerves, doctors call it neuropsychiatric lupus. In 1999 the American College of Rheumatology (ACR) published case definitions for 19 neuropsychiatric syndromes in SLE, and cognitive dysfunction was one of them. The same committee proposed a short neuropsychological test battery for detecting it.
How often cognitive dysfunction is found depends almost entirely on how hard researchers look and where they set the cutoff:
• Population sample: In a Finnish study of 46 people with SLE from a defined region, Ainiala and colleagues found cognitive dysfunction in 37 (81%). Most cases were mild, and when mild syndromes were excluded the share with any neuropsychiatric lupus fell from 91% to 46%.
• Pooled studies: A 2018 meta-analysis by Rayes and colleagues combined 35 studies of 2,463 patients that used comprehensive test batteries and estimated a prevalence of 38%. Studies using a shorter computerized battery averaged 26%. People with SLE were 2.8 times as likely as healthy people to be classified as impaired, and 1.8 times as likely as people with rheumatoid arthritis.
• Same data, different rules: In the childhood-onset study above, three published definitions classified 7.3%, 34.1% and 63.4% of the same patients as impaired. None of the methods found a significant difference from the healthy control group.
A 2021 review of 43 studies that used a full test battery found that none used the ACR battery exactly as published, and cutoffs ranged from 1 to 3 standard deviations below the norm. The wide range of published prevalence figures says more about these definitions than about lupus.
Which thinking skills are affected
The cognitive profile in lupus is uneven. Overall reasoning tends to hold up while speed, attention and some kinds of memory lag behind.
• Attention and visuospatial skills: Ginsburg and colleagues tested randomly selected outpatients and found that people with SLE did worse than people with rheumatoid arthritis on a test of attention, independent of age, education and steroid use. Differences on visuospatial tests were smaller and did not pass the study's strict threshold for multiple comparisons.
• Memory: Monastero and colleagues found impairment in 26.9% of people with SLE without neuropsychiatric symptoms and 52.2% of those with them. Both groups did worse than controls on long-term memory and on drawing or building designs.
• Neuropsychiatric versus other lupus: A meta-analysis by Zabala and colleagues found greater deficits in neuropsychiatric lupus for visuomotor coordination, attention, executive function, visual learning and memory, and word fluency.
• Processing speed: Slower processing is one of the most common findings. Our guide to the Processing Speed Index explains how that part of an IQ test works and why a low score can pull down a full-scale result.
People with lupus often describe this as "brain fog." In Ginsburg's study, patients' own reports of cognitive difficulty lined up with their objective test results, so these complaints deserve to be taken seriously. Slower processing is also a central finding in another autoimmune condition that affects the brain, covered in our article on IQ and multiple sclerosis.
What drives the differences, and do they change over time?
Several factors have been linked to poorer cognitive performance in lupus, though none explains it fully.
• Antiphospholipid antibodies: These antibodies raise the risk of blood clots. In the San Antonio lupus study of 123 patients followed for at least 3 years, persistently positive antiphospholipid antibodies were associated with declining cognitive function. Tektonidou and colleagues found cognitive deficits in 42% of 60 people with antiphospholipid syndrome compared with 18% of matched healthy controls, with links to white matter lesions on MRI.
• Depression and distress: In the Monastero study, depression was the only clinical variable that predicted cognitive performance. Kozora found psychological distress in 42% of people with SLE without central nervous system disease, compared with 6% of controls.
• Medication and disease severity: The San Antonio study also linked consistent prednisone use to declining cognition in middle-aged patients, but the authors could not rule out that steroid use was a marker for more severe disease.
• Education: Less education was another predictor of cognitive decline in the San Antonio cohort, a reminder that test scores always reflect more than the disease.
Over time, cognitive problems in lupus tend to be stable or to fluctuate, and steady decline is uncommon. Carlomagno and colleagues retested 51 patients and found that impairment persisted in most of those who had it, with no progressively falling scores on any test.
For anyone affected, the practical step is a full assessment. A rheumatologist can look at possible contributors such as active disease, medication effects or depression, and a clinical neuropsychologist can measure which specific skills are affected and track them over time.
Frequently asked questions
Does lupus lower your IQ?
For most people, no. Studies generally find full-scale IQ in the average range, while narrower skills such as attention, processing speed and memory are more likely to be affected.
What is lupus brain fog?
It is the everyday description of cognitive dysfunction in lupus: trouble concentrating, slower thinking and forgetfulness. Patients' own reports of these problems tend to match their results on objective tests.
How common are cognitive problems in lupus?
Estimates range from under a quarter to over 80% of patients, depending on the definition and tests used. A large meta-analysis put the figure at about 38% in studies using comprehensive test batteries.
Do cognitive problems in lupus get worse over time?
Follow-up studies mostly find stable or fluctuating performance, without steady decline. Persistent antiphospholipid antibodies have been linked to slow worsening in some patients.
Who should I see about memory or thinking problems with lupus?
Start with your rheumatologist, who can check for active disease, medication effects and other medical causes. A clinical neuropsychologist can carry out a full cognitive assessment.
The takeaway
The research on lupus IQ points to average full-scale scores for most people, alongside real weaknesses in speed and attention that standard IQ totals can hide. Prevalence figures vary enormously because definitions vary, and antiphospholipid antibodies and depression are among the factors most often linked to poorer performance. If you want a reliable picture of your own reasoning ability, a professionally developed IQ test can provide one, while lupus-related thinking problems call for a clinical neuropsychological assessment.
References
1. ACR Ad Hoc Committee on Neuropsychiatric Lupus Nomenclature. (1999). The American College of Rheumatology nomenclature and case definitions for neuropsychiatric lupus syndromes. Arthritis & Rheumatism, 42(4), 599-608. [doi.org (ACR case definitions, 1999)](. doi.org
2. Skeel, R. L., Johnstone, B., Yangco, D. T., Walker, S. E., & Komatireddy, G. R. (2000). Neuropsychological deficit profiles in systemic lupus erythematosus. Applied Neuropsychology, 7(2), 96-101. [doi.org/10.1207/S15324826AN0702_5](. doi.org
3. Kozora, E., Thompson, L. L., West, S. G., & Kotzin, B. L. (1996). Analysis of cognitive and psychological deficits in systemic lupus erythematosus patients without overt central nervous system disease. Arthritis & Rheumatism, 39(12), 2035-2045. [doi.org/10.1002/art.1780391213](. doi.org
4. Williams, T. S., Aranow, C., Ross, G. S., Barsdorf, A., Imundo, L. F., Eichenfield, A. H., ... Levy, D. M. (2011). Neurocognitive impairment in childhood-onset systemic lupus erythematosus: Measurement issues in diagnosis. Arthritis Care & Research, 63(8), 1178-1187. [doi.org/10.1002/acr.20489](. doi.org
5. Nowling, T. K., Kral, M., Wolf, B., Gilkeson, G., & Ruth, N. M. (2021). Formal neurocognitive function and anti-N-methyl-D-aspartate receptor antibodies in paediatric lupus. Lupus Science & Medicine, 8(1), e000462. [doi.org/10.1136/lupus-2020-000462](. doi.org
6. Ainiala, H., Loukkola, J., Peltola, J., Korpela, M., & Hietaharju, A. (2001). The prevalence of neuropsychiatric syndromes in systemic lupus erythematosus. Neurology, 57(3), 496-500. [doi.org/10.1212/WNL.57.3.496](. doi.org
7. Rayes, H. A., Tani, C., Kwan, A., Marzouk, S., Colosimo, K., Medina-Rosas, J., ... Touma, Z. (2018). What is the prevalence of cognitive impairment in lupus and which instruments are used to measure it? A systematic review and meta-analysis. Seminars in Arthritis and Rheumatism, 48(2), 240-255. [doi.org/10.1016/j.semarthrit.2018.02.007](. doi.org
8. Yuen, K., Green, R., Bingham, K., Ruttan, L., Lee-Kim, V., Tartaglia, M. C., ... Touma, Z. (2021). Metrics and definitions used in the assessment of cognitive impairment in systemic lupus erythematosus: A systematic review. Seminars in Arthritis and Rheumatism, 51(4), 819-830. [doi.org/10.1016/j.semarthrit.2021.05.018](. doi.org
9. Ginsburg, K. S., Wright, E. A., Larson, M. G., Fossel, A. H., Albert, M., Schur, P. H., & Liang, M. H. (1992). A controlled study of the prevalence of cognitive dysfunction in randomly selected patients with systemic lupus erythematosus. Arthritis & Rheumatism, 35(7), 776-782. [doi.org/10.1002/art.1780350711](. doi.org
10. Monastero, R., Bettini, P., Del Zotto, E., Cottini, E., Tincani, A., Balestrieri, G., ... Padovani, A. (2001). Prevalence and pattern of cognitive impairment in systemic lupus erythematosus patients with and without overt neuropsychiatric manifestations. Journal of the Neurological Sciences, 184(1), 33-39. [doi.org/10.1016/S0022-510X(00)00492-5](. doi.org
11. Zabala, A., Salgueiro, M., Sáez-Atxukarro, O., Ballesteros, J., Ruiz-Irastorza, G., & Segarra, R. (2018). Cognitive impairment in patients with neuropsychiatric and non-neuropsychiatric systemic lupus erythematosus: A systematic review and meta-analysis. Journal of the International Neuropsychological Society, 24(6), 629-639. [doi.org/10.1017/S1355617718000073](. doi.org
12. McLaurin, E. Y., Holliday, S. L., Williams, P., & Brey, R. L. (2005). Predictors of cognitive dysfunction in patients with systemic lupus erythematosus. Neurology, 64(2), 297-303. [doi.org/10.1212/01.WNL.0000149640.78684.EA](. doi.org
13. Tektonidou, M. G., Varsou, N., Kotoulas, G., Antoniou, A., & Moutsopoulos, H. M. (2006). Cognitive deficits in patients with antiphospholipid syndrome: Association with clinical, laboratory, and brain magnetic resonance imaging findings. Archives of Internal Medicine, 166(20), 2278-2284. [doi.org/10.1001/archinte.166.20.2278](. doi.org
14. Carlomagno, S., Migliaresi, S., Ambrosone, L., Sannino, M., Sanges, G., & Di Iorio, G. (2000). Cognitive impairment in systemic lupus erythematosus: A follow-up study. Journal of Neurology, 247(4), 273-279. [doi.org/10.1007/s004150050583](. doi.org
Hero image: IFI-Nuclear and inespecific citoplasmatic stain Hep-2 Line cells, by J3D3, licensed CC BY-SA 3.0 (creativecommons.org/licenses/by-sa/3.0). Via Wikimedia Commons.
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