Researchers are discovering that post-traumatic stress disorder (PTSD) is a significant risk factor in developing dementia.

Until now, researchers didn’t know whether the kinds of medications used for people with PTSD could increase risks for dementia. (These medications include including antidepressants, antipsychotics, sedatives, or tranquilizers.)

A new study, published in the Journal of the American Geriatrics Society, examined this connection.

In their study, researchers examined information from 3,139,780 veterans aged 56 and older. At the beginning of the study, in 2003, the veterans were receiving healthcare from a Veterans Health Administration facility. Almost all the veterans were male and 82 per cent were white.

Of the veterans in the study, 5.4 per cent had been diagnosed with PTSD. As the researchers looked at the data over the study’s nine-year follow-up period, they also included veterans who were diagnosed with dementia.

Research has previously shown that veterans with PTSD are more likely to have health problems linked to a higher risk for dementia. These include traumatic brain injury, diabetes, chronic obstructive pulmonary disease (COPD), psychiatric disorders, substance abuse, and other health issues.

In this study, researchers discovered that taking certain antidepressants, tranquilizers, sedatives, or antipsychotic medications significantly increased veterans’ risks for developing dementia compared to the risks for veterans who didn’t take such medications.

Medicines that significantly increased dementia risk included:

  • Selective serotonin reuptake inhibitors (SSRIs)
  • Novel antidepressants
  • Atypical antipsychotics

The increase in the risk of dementia for veterans taking the drugs was the same whether or not they were diagnosed with PTSD. (This is compared to veterans who weren’t taking these drugs.)

What’s more, veterans who used three classes of medications were also more likely to be diagnosed with dementia whether or not they had PTSD.

These medicines include:

  • Novel antidepressants
  • Serotonin-norepinephrine reuptake inhibitors (SNRIs)
  • Benzodiazepines

The researchers noted that an interaction among these ‘psychoactive’ drugs could potentially affect how PTSD impacts a person’s risk for developing dementia. The researchers concluded that further research should be conducted to learn more about PTSD and psychoactive drugs, including dosage, how long to take the medications, and which people could most benefit from them.