(WGHP) — Bruce Willis’ condition has worsened about a year after he was diagnosed with aphasia, his family said in a statement released on Thursday.

Willis has frontotemporal dementia, also known as FTD, which his family says is a “cruel disease” and the most common form of dementia.

“Today there are no treatments for the disease, a reality that we hope can change in the years ahead. As Bruce’s condition advances, we hope that any media attention can be focused on shining a light on this disease that needs far more awareness and research,” the statement reads.

Willis stepped away from acting in March 2022 after initially being diagnosed with aphasia, which is a condition that is “impacting his cognitive abilities,” according to a statement shared by his family.

Aphasia, which can cause varying degrees of impairment in speech or understanding language, currently affects more than 2 million Americans, the National Aphasia Association estimates.

The condition often results from a stroke or brain injury but can develop over time due to brain tumors or progressive neurological disease.

Aphasia can affect people of any age, though most who are diagnosed are “middle-aged or older,” according to the National Institute of Health.

There are several different types of aphasia that fall within two categories: fluent and nonfluent.

Fluent aphasia generally develops from damage to the temporal lobe, and can result in a common form of the condition called Wernicke’s aphasia, which may cause a person to have trouble understanding speech, or speak in “long, complete sentences that have no meaning,” the NIH writes.

Nonfluent aphasia, found more commonly in those with damage to the frontal lobe, can result in Broca’s aphasia, a type that may hinder speech and cause a person to speak in short phrases or smaller words, despite generally having a better understanding of speech.

There are, however, many forms of aphasia that may have different symptoms.

“Nearly all patients with aphasia have word-finding difficulties – that is, coming up with the correct name of persons, places, things, or events,” the Cleveland Clinic notes.

Patients who suffer aphasia as a result of a brain injury may recover some of their language and cognitive abilities on their own, though many may not.

Rehabilitation programs focusing on speech and language therapy can offer further help.

Drug therapies are also being explored as an “experimental approach” to treatment, according to the NIH.

“Some studies are testing whether drugs that affect the chemical neurotransmitters in the brain can be used in combination with speech-language therapy to improve recovery of various language functions,” the agency writes.