MS is a disease in which the body’s immune system attacks myelin, the fatty white substance that insulates and protects the nerves. Symptoms of MS may include fatigue, numbness, tingling or difficulty walking.

“When it comes to MS treatment, the earlier the better,” said study author Alvaro Cobo-Calvo, MD, PhD, of the Multiple Sclerosis Center of Catalonia and the Autonomous University of Barcelona in Spain. “Our study found that starting treatment within six months after the first symptoms is associated with a lower risk of disability over time.”

For the study, researchers looked at 580 people with a first episode of symptoms, such as tingling, numbness, muscle weakness or problems with balance, who received at least one disease-modifying drug.

Researchers divided participants into three groups: 194 people who had their first treatment with an MS drug within six months after the first episode of symptoms, 192 people who had first treatment between six months and 16 months, and 194 people who had first treatment after more than 16 months.

Researchers monitored people’s disability levels and brain scans for damage to the brain and spinal cord from the disease for an average of 11 years. Disability scores ranged from zero to 10, with higher scores indicating more disability.

The earliest treatment group had a 45% lower risk of reaching a disability score of three by the end of the study than those in the latest treatment group. A score of three indicates people can still walk unassisted but have moderate disability in one of eight areas, such as motor function, vision or thinking skills, or mild disability in three or four areas. A total of 42 people in the earliest treatment group, or 23%, reached a score of three, compared to 75 people, or 43%, in the latest treatment group.

The earliest treatment group also had a 60% lower risk of moving to the next stage of the disease, called secondary progressive MS, than people in the latest treatment group. In this stage, disability gets steadily worse. A total of 14 people in the earliest treatment group, or 7%, were diagnosed with secondary progressive MS compared to 43 people in the latest treatment group, or 23%.

They also found that people with the earliest treatment were 50% more likely to remain stable at their disease level one year after their initial treatment than those in the latest treatment group.

“Altogether, our results support the robustness and effectiveness of very early treatment to halt long-term disability progression, and stress that earlier detection and treatment is encouraged,” Cobo-Calvo said.

Researchers also found that people from the earliest treatment group had a lower disability progression rate and lower severe disability in a self-reported test compared to those in the latest treatment group.

A limitation of the study was that it only included patients between ages 16 to 50 at the time of first symptoms, so the results could not be applied to patients over age 50, or late-onset multiple sclerosis.

The study was supported by the European Regional Development Fund, Carlos III Health Institute, Spanish Multiple Sclerosis Network and the Agency for Management of University and Research Grants in Spain.