Internalize at your peril: internalizing disorders as risk factors for dementia-cohort study

Area of Science:

• Neuroscience
• Psychiatry
• Epidemiology

Background:

• Comorbid anxiety and depression are common but their independent association with dementia risk is understudied.
• Internalizing disorders, encompassing anxiety and depression, are prevalent globally, affecting one in five adults.
• Separating anxiety and depression can be challenging, necessitating a broader assessment of internalizing disorders.

Purpose of the Study:

• To investigate internalizing disorders as independent risk factors for dementia.
• To assess the association between a prior diagnosis of internalizing disorders and the subsequent risk of dementia.
• To examine sex-specific differences in dementia risk following internalizing disorder diagnosis.

Main Methods:

• Retrospective prospective comparative cohort study utilizing New Zealand's National Minimum Dataset.
• Analysis of hospital discharge data for individuals aged 50-54 years between 1988 and 1992.
• Parametric survival models were used to estimate hazard ratios (HRs) for incident dementia after a 10-year latency interval.

Main Results:

• A total of 37,631 eligible patients were included, with 1594 diagnosed with incident dementia.
• Patients with prior internalizing disorders had higher rates of dementia (572 vs. 303 per 100,000 PYAR).
• Internalizing disorders were associated with a 57% increased risk of dementia (adjusted HR=1.57), with females showing a near doubling of risk (adjusted HR=1.80).

Conclusions:

• Internalizing disorders represent a significant risk factor for developing dementia.
• The increased dementia risk associated with internalizing disorders persists for at least 10 years post-diagnosis.
• Females with internalizing disorders face a substantially higher risk of dementia.