In this nationwide cohort study, researchers assessed 7,300,395 people 15 years and older living in Denmark from 1980 until 2016. They analyzed medical contact for head injury, stroke, epilepsy, polyneuropathy, diseases of myoneural junction, Parkinson disease, multiple sclerosis, central nervous system infections, meningitis, encephalitis, amyotrophic lateral sclerosis, Huntington disease, dementia, intellectual disability, and other brain diseases from 1977 through 2016.
The study’s primary endpoint was defined as death by decide, and the researchers estimated this outcome using Poisson regressions, adjusted for sociodemographics, comorbidity, psychiatric diagnoses, and self-harm.
According to the results of the study, than 7.3 million individuals observed over 161.935,233 person-years, 35,483 died by suicide (median duration of follow-up, 23.6 years; interquartile range, 10.0-37.0 years; mean age, 51.9 years; SD, 17.9 years). Of those, the results showed that 14.7% were diagnosed with a neurological disorder, equivalent to a suicide rate of 44.0 per 100.000 person-years compared with 20.1 per 100,000 person-years among individuals not diagnosed with a neurological disorder.
The researchers observed that people diagnosed with a neurological disorder had an adjusted IRR of 1.8 (95% CI, 1.7 to 1.8) compared with those not diagnosed. The excess adjusted IRRs were 4.9 (95% CI, 3.5 to 6.9) for amyotrophic lateral sclerosis, 4.9 (95% CI, 3.1 to 7.7) for Huntington disease, 2.2 (95% CI, 1.9 to 2.6) for multiple sclerosis, 1.7 (95% CI, 1.6 to 1.7) for head injury, 1.3 (95% CI, 1.2 to 1.3) for stroke, and 1.7 (95% CI, 1.6 to 1.8) for epilepsy.
Moreover, the association varied according to time since diagnosis with an adjusted IRR for 1 to 3 months of 3.1 (95% CI, 2.7 to 3.6) and for 10 or more years, 1.5 (95% CI, 1.4 to 1.6, P < .001). Compared with those who were not diagnosed with a neurological disorder, those with dementia had a lower overall adjusted IRR of 0.8 (95% CI, 0.7 to 0.9), which was elevated during the first month after diagnosis to 3.0 (95% CI, 1.9 to 4.6; P < .001). The absolute risk of suicide for people with Huntington disease was 1.6% (95% CI, 1.0% to 2.5%).
Incredibly important study, although results unsurprising. Rates of suicide in ppl with neurological disorders nearly double that of ppl without. Absolute risk difference still small though. Highest rates found in ALS and in Huntington disease.https://t.co/CbKuc1ZsTw
— Tom Pollak (@tompollak) February 4, 2020
The researchers wrote in conclusion that: “In Denmark from 1980 through 2016, there was a significantly higher rate of suicide among those with a diagnosed neurological disorder than persons not diagnosed with a neurological disorder. However, the absolute risk difference was small.”
This is one of the reasons we are studying NBTX-001 in neurodegenerative diseases. Association Between Neurological Disorders and Death by Suicide in Denmark https://t.co/VzbAD8Mlcd
— Nobilis Therapeutics (@NobilisTx) February 5, 2020
Association Between Neurological Disorders & Death by Suicide—Highest for Huntington Disease & ALS but Common Disorders (Head Injury, Stroke, Epilepsy, etc.) Also Associated w/ Higher Suicide Rates #suicide #Neurology #stroke #ALS #Epilepsy #Huntingtonhttps://t.co/u9zbCcHKC5
— Ken Pope, Ph.D., ABPP (@KenSPope) February 5, 2020