Scoliosis in adulthood can get worse, but it depends on various factors.
One factor is the degree of scoliosis; the more severe the scoliosis, the more it tends to deteriorate. Scientific studies in this regard highlight a trend towards deterioration for those at the end of growth having scoliosis from 30 degrees Cobb and above, while at the exceeding threshold of 45/50 degrees of scoliosis, it is almost sure that with the passing of the years, the scoliosis will worsen.
Another critical factor is lifestyle. Having an active life and participating in sporting activities helps maintain good muscle tone so as to provide support to the spine and counteract the tendency of the curves to collapse.
Braces in adulthood do not improve scoliosis; with no more bone growth, it is impossible to condition the vertebral shape.
The brace can only be indicated for an aesthetic issue in very early adulthood when it is particularly compromised. The other indication of the brace in adults is pain; in this case, it is advisable to assess with a specialist physician.