The initial symptoms of CJD are psychological. A common initial symptom is depression.

The condition progresses rapidly, and other symptoms soon appear. In sporadic CJD, these tend to be confusion and memory problems. In variant CJD, they tend to be a worsening of the depression, anxiety, delusions (strong beliefs in things that are obviously not true) and hallucinations (seeing or hearing things that are not there).

Due to the symptoms, in its early stages CJD can often be misdiagnosed as dementia or depression.

Further symptoms follow as the person's nervous system continues to worsen. These include:

• involuntary jerks and tremors,
• sensations of cold or pain,
• a sense that the skin feels sticky,
• loss of coordination,
• muscle paralysis,
• problems seeing or hearing,
• difficulty speaking, and
• difficulty swallowing.

Most people with sporadic CJD will die within six months of diagnosis. Most people with variant CJD will die within a year of diagnosis.