Changes in how someone talks, follows a conversation or behaves are part of the illness, not something the person is choosing. Knowing that does not make it easy to live with.
Why does behaviour change?
The illness affects the parts of the brain used for memory, mood, judgement and movement. Mood symptoms are common at any stage.
The UK recommendations for CJD care published in 2026 treat challenging behaviour as communication of an unmet need. The practical advice that follows from this is to look for a trigger first, and to change the surroundings before reaching for a medicine. Light, sound and touch are specific triggers named in that guidance, and they also set off the muscle jerks called myoclonus.
Those recommendations also note that such symptoms can settle quickly on their own, so watching and waiting is often the right thing to do rather than a way of avoiding action.
What might be behind distress?
Pain is the one most often missed. In someone who can no longer say they are in pain, the 2026 recommendations say pain may show itself as agitation or restlessness. What the family notices is treated as important information: the guidance calls the carer’s account invaluable in working out whether someone is in pain.
Other ordinary causes are worth checking in the same way: needing the toilet, being too hot or cold, being hungry or thirsty, a noisy room, too many people, an unfamiliar person helping with food, or being tired.
What helps with talking?
Fewer words, one idea at a time, and time to answer. Reducing background noise helps more than speaking louder. Familiar faces and a calm room help.
Speech and language therapists advise on this and on swallowing, and the 2026 recommendations include them in the care team from early on. The CJD Foundation publishes a speech and language handout on communication, swallowing and memory that you can take to appointments.
When speech has gone, people still take in tone, touch and presence. Sitting with someone, holding a hand, and familiar music are not small things.
When are medicines used?
When distress or risk is severe, and under a doctor’s direction. Antidepressants are described in the 2026 recommendations as often helpful and generally well tolerated. Antipsychotic medicines may help severe agitation or psychotic symptoms, on limited evidence. Where one medicine can treat more than one symptom, specialists prefer that to adding several.
Some medicines can make things worse, and the guidance asks clinicians to review anything that increases the risk of falls or worsens movement symptoms. Opioid painkillers and antipsychotics can both aggravate myoclonus.
This is a decision for the treating team, who know the person, the other medicines and the stage of the illness. If you think a medicine has changed someone for the worse, say so, and ask for a review.
Who to ask
The person coordinating care, and the palliative care team if one is involved. A specialist prion service can advise the local team, and in the UK it can do so without the family arranging it.
Related pages: daily care at home, caring for yourself and the care hub.