Researchers from Fudan University in China identified that individuals with untreated depression face a higher risk of later developing dementia. The study, published in Biological Psychiatry, highlights how lack of treatment can influence long-term cognitive health.
Involving more than 350,000 people diagnosed with dementia, the study collected self reports on past depressive episodes and the treatments used for this condition. Investigators also assessed current depressive symptoms at the time of enrollment and categorized them into four levels: rising, falling, persistent high intensity, and low intensity.
Participants were then separated into two cohorts. One group consisted of individuals who had previously used antidepressants and received psychotherapy. The other group included those who did not pursue treatment for depression following their diagnosis.
The findings showed that individuals with untreated depression were about 30 percent more likely to develop dementia compared with those who received appropriate treatment. Moreover, those who skipped treatment often exhibited high intensity depressive symptoms, a pattern that correlated with a lower quality of life and more pronounced daily challenges. Previously, it was described as a possible symptom of depression that can appear in childhood, a notion that has since evolved with newer research into mood disorders and early life risk factors.