Medically reviewed by Nancy Hammond, M.D. — Written by Rachael Zimlich, RN, BSN — Updated on February 12, 2026

Key takeaways

• Stress, mood changes, and emotions such as anxiety and depression can worsen motor symptoms in people with Parkinson’s disease.
• Medications, especially levodopa, can cause complications and fluctuating responses. You may need dosage adjustments or additional treatments. Certain other medications can also aggravate Parkinson’s symptoms.
• Imbalances in gut bacteria and certain foods, such as processed foods and red meats, may affect the central nervous system and worsen Parkinson’s progression, while Mediterranean-type diets may help.

Parkinson’s disease is a chronic, progressive neurological disease. There’s no cure, and in the years after diagnosis, many people with this condition may notice their symptoms fluctuate or worsen.

What worsens Parkinson’s disease?

If you have Parkinson’s disease, there are various factors that may worsen your symptoms. Common triggers include the following.

Chronic stress

Research has identified chronic stress as one of the possible initial triggers for the onset of Parkinson’s disease.

In one survey in 2021Trusted Source, people with Parkinson’s disease reported increases in the following symptoms when their stress levels were higher:

• tremors
• movement problems
• sleep disturbances
• depression
• balance and gait
• dyskinesias like muscle weakness or twitching
• memory problems
• speech and communication difficulties

The study authors noted that tremors seemed to be the symptom most affected by stress.

Emotions

Stress, emotional turmoil, and other mood changes can have an effect on symptoms in people with Parkinson’s disease. Anxiety and depression are common emotional symptoms that often develop in those with the condition.

Research has found that motor symptoms were worse in people with Parkinson’s who were in a depressed, anxious, or otherwise emotional state.

Read more here: Common Triggers of Parkinson's Disease Symptoms

Study will evaluate safety, tolerability, and pharmacokinetics

Written by Andrea Lobo | February 23, 2026

• A Phase 1b trial of SER-252 (POZ-apomorphine) in advanced Parkinson’s disease has enrolled its first patient.
• SER-252 is designed to reduce “off” episodes by providing continuous dopaminergic stimulation.
• The trial is evaluating safety and early efficacy, and the therapy is designed for subcutaneous self-administration.

A Phase 1b clinical trial evaluating Serina Therapeutics’s SER-252 (POZ-apomorphine) in people with advanced Parkinson’s disease has enrolled its first patient, the company announced.

The global registrational trial is evaluating the treatment’s safety, tolerability, pharmacokinetics, and preliminary efficacy. The first group of participants is being enrolled in Australia, where the company has an operational presence. Serina said it expects to begin dosing in the first quarter and plans to provide updates as enrollment progresses.

Phase 1b study designed to support regulatory development

Serina said the trial is intended to generate data to support future regulatory submissions.

“Enrolling our first patient represents an important operational milestone as we advance SER-252 into the clinic,” Steve Ledger, Serina’s CEO, said in a company press release. “Our team has built a strong operational presence in Australia, working closely with leading Parkinson’s disease specialists and patient advocacy organizations to support efficient enrollment.”

Serina has said it plans to pursue SER-252 through the U.S. Food and Drug Administration’s 505(b)(2) regulatory pathway, which allows companies to rely in part on data from previously approved drugs.

Parkinson’s disease is caused by the progressive loss of dopaminergic neurons, the nerve cells that produce dopamine, a chemical messenger the brain uses to coordinate movement. Levodopa is a mainstay treatment that helps ease motor symptoms by providing a precursor molecule the body converts into dopamine.

However, long-term levodopa use can cause side effects such as dyskinesia, or involuntary movements, and many patients experience “off” episodes, periods of reduced symptom control that occur between doses.

Read more here: First patient enrolled in new SER-252 trial for advanced Parkinson's disease

Written by Margarida Maia, PhD | February 16, 2026

• Women with Parkinson's show more uneven muscle contraction than men.
• Differences stem from motor unit firing variability and discharge rates.
• This informs personalized diagnostics and sex-specific Parkinson's treatments.

Women with Parkinson’s disease have more uneven and unstable muscle contraction than men, even when their clinical symptoms are similar, a study found.

The differences are related to the firing of motor units; a motor unit is a single nerve cell and the muscle fibers it controls, which together produce movement.

Findings from the study, by researchers at Kanazawa University in Japan, could “contribute to the development of personalized diagnostic methods and treatment strategies that account for sex-specific factors, ultimately leading to more effective interventions and improved quality of life,” according to a university press release.

The study, “Sex Differences in Motor Unit Behavior in Patients with Parkinson’s Disease,” was published as a research report in the European Journal of Neuroscience by an international team of researchers.

Growing evidence suggests differences between men and women in how common Parkinson’s is and how its motor and nonmotor symptoms manifest. The researchers sought to determine whether there are sex differences in motor unit firing abnormalities in Parkinson’s patients.

Read more here: Parkinson's muscle firing patterns different from women than for men