Do you have a somewhat twisted sense of humor? That could be a good indication that you’re going to get dementia, published the study in the Journal of Alzheimer’s Disease, which examined families and friends of 48 dementia patients who could describe their behavior 15 years before they came down with the disease, according to a Guardian report.

They noticed a change in their senses of humor, which tended to take on a more dark tone. The patients would often laugh at inappropriate moments, such as during a report on a natural disaster or a poor parking job. One even laughed when a loved one accidentally hurt herself.

These patients were also more likely to enjoy slapstick comedies like Mr. Bean compared to more absurdist comedy like Monty Python.

According to the report, a respondent wrote: “Early on, [they] laughed very loudly at things that were only mildly funny, flippant or over the top; now laughs all the time at things that are not particularly funny and will say ‘I’m laughing and I’m not sure why I’m laughing.’ … When I badly scalded myself the other year, [they] thought it was hilarious.”

Basically, humor had to become more obvious for them, and they stopped appreciating more sophisticated humor. Dirty and inappropriate jokes became more popular.

Alzheimer’s and dementia are disease of the brain characterized by memory loss that worsens over time and often leads to the complete incapacitation of the sufferer. It begins with difficulty to remember recent events and eventually results in problems with language and disorientation, as well as mood swings and behavioral problems. Alzheimer’s accounts for about two-thirds of dementia cases.