There is a lot we still don’t know about Parkinson’s disease (PD). Research is key to unlocking its causes, developing life-changing treatments and ultimately, discovering a cure. One way people with PD can help scientists to better understand the disease is through participating in research. Learn more about the process and how to get involved.

There are two types of clinical studies: an observational study and a clinical trial.

What is an observational study?

An observational study is when researchers observe people and try to figure out what factors affect their health and their likelihood of developing certain diseases, like PD. For example, researchers might look at how different lifestyles affect Parkinson's. Observational studies measure or survey participants rather than applying treatments, like medications.

• Cohort (or registry) studies. Follow people with a common characteristic over time.
• Case-control studies. Focus on people who have developed a disease and compare them to a group of people who do not have the disease.

What is a clinical trial?

A clinical trial is a research study with human participants that aims to answer specific questions about potential medical treatments. When researchers are developing a new treatment for PD, such as a drug, surgery, therapy or a device, they make sure it works by conducting a clinical trial. These trials help researchers and doctors learn what does and doesn’t work in treating diseases like PD.

Types of clinical trials

• Therapeutic. Test safety and effectiveness (efficacy) of a potential PD therapy — drug or non-drug — or a different way to use an existing therapy.
• Diagnostic. Look for biomarkers or a measurable sign in the body that can diagnose PD or track its progression.
• Genetic. Help understand how genes affect PD.
• Preventative. Aim to find ways to prevent someone from developing PD.

Phases of clinical trials

Treatments are put through the rigorous process of clinical trials before the U.S. Food and Drug Administration (FDA) can consider approving them.

• Phase I. Tests a potential treatment for the first time in a small group of people (with the disease and without) to evaluated safety and dosage and identify side effects.
• Phase II. Further evaluates the safety of a treatment in a small group of people from the affected population and provides early evidence of its effectiveness.
• Phase III. In a larger group of people, determines if the treatment benefits participants and if its benefits outweigh its risks.
• Phase IV. After receiving FDA approval, researchers collect and look over additional information about a treatment, including risks, benefits and how it is best used.

Risks of clinical trial participation

• The study treatment might not work. However, unsuccessful studies are important in learning more about PD.
• Not receiving the study treatment. You might receive a placebo (like a sugar pill) that lets researchers compare the group that receives the treatment to a group that does not.
• Experiencing unwanted side effects. These may include known side effects and new ones that might appear during the study. They can be minor or serious in nature.

Informed consent

It is required that you give your informed consent prior to taking part in a study. It ensures that researchers have given you complete information and that you fully understand the trial, risks and your role as a participant.

Why Participate in Clinical Studies?

Your participation in clinical studies can:

• Advance Parkinson’s prevention, treatments and a cure. Almost all of what we know about Parkinson’s is due to research.
• Give you early access to potentially helpful treatments not yet accessible. This does not replace your normal treatment.
• Contribute to the diversity of research participants. Individuals can respond differently to therapies.
• Play a part even if you don’t have Parkinson’s. Many trials are looking for “healthy controls” or people who do not have PD.

Which Studies are Right for You?

Some studies are as simple as filling out a survey, while others can involve procedures or treatments. You may want to think about certain requirements, such as the number of times you must visit the study site, the length of each visit, the number and types of tests you will have to do and how long you need to be in the trial. Keep other factors in mind, like commuting to the study site.

Be sure to discuss participating in a trial with:

• Your neurologist. Share information about the study. Your neurologist can help you evaluate a specific study and possibly recommend additional studies for you.
• Your family. Joining a trial can affect members of your family. Involve your family in your decision-making process. You might go to them for emotional support.

Ongoing Research

In addition to funding research grants, Parkinson’s Foundation research initiatives include:

PD GENEration: Mapping the Future of Parkinson’s

This national study offers genetic testing for PD-related genes and genetic counseling at no cost for people with Parkinson’s. Participation can be either in-person or from home through a telemedicine appointment. For more information and to enroll visit Parkinson.org/PDGENEration.

Parkinson’s Outcomes Project

A clinical study among 13,000+ people with PD conducted at select Parkinson’s Foundation Centers of Excellence. Read more findings at Parkinson.org/Outcomes.

Parkinson’s Foundation Surveys

This initiative advances Parkinson’s care by better understanding the experiences of people living with PD and their care partners and sharing findings with the community. Make your voice heard and sign up at Parkinson.org/Surveys.

TOPAZ

This study tests if a medication, called zoledronate, can prevent bone fractures in people with PD. Participation is done from home. To learn more, visit TopazStudy.org.

Finding a Parkinson's Study

• Clinicaltrials.gov is a database of privately and publicly funded clinical studies conducted around the world.
• National Institutes of Health (NIH) Clinical Research Trials and You is an online resource to help people learn more about clinical trials. Visit nih.gov/health/clinicaltrials.
• Find the latest in Parkinson’s’ research and more information on joining a PD research study. Visit Parkinson.org/Research.

The cause of Parkinson’s disease (PD) is unknown, but scientists believe that a combination of genetic and environmental factors are the cause. The extent to which each factor is involved varies from person to person. Regardless of how a person gets Parkinson’s — through genetics or environment or a combination of both — every person with PD experiences a loss of dopamine in the brain, along with symptoms and a progression of their disease that is unique to them.

Understanding Genetics

Genetics is the field of science that examines how traits are passed down, or inherited, from parents to children through genes. The study of genetics begins with our DNA. Think of our DNA as a cookbook that contains about 23,000 genes, or recipes, that make us who we are. A gene is like a recipe used to build a protein (that help our bodies perform different jobs to function normally). Changes, known as mutations, in our genes can change the recipe — altering the shape and normal function of proteins in our body. Changes in our genes are mostly harmless, but in some cases, they can affect our risk of getting a disease.

In addition to genetics, environmental factors and lifestyle choices strongly determine if Parkinson’s will develop. Understanding the role of genes and PD can help pave the way to understanding the biological causes of disease and develop novel therapies to treat Parkinson’s.

Understanding the connection between Parkinson’s and genetics can help us understand how the disease develops and ultimately how it can be treated or cured.

Parkinson’s Genes

Parkinson’s is rarely hereditary. Genetics cause about 10% to 15% of all Parkinson’s. If a person tests positive for a certain gene mutation associated with Parkinson’s — such as a mutation in LRRK2, GBA and SNCA genes — their risk may increase, but they may never develop Parkinson’s. In some families, changes (or mutations) in certain genes are inherited or passed down from generation to generation. A handful of ethnic groups, like the Ashkenazi Jews and North African Arab Berbers, more commonly carry genes linked to PD and researchers are still trying to understand why. Over the years, scientists have studied DNA from people with Parkinson’s, comparing their genes. They discovered dozens of gene mutations linked to Parkinson’s. These genes are now being researched and studied for what role they play in Parkinson’s.

There are ongoing clinical trials testing therapies to treat people who have Parkinson’s and carry certain gene mutations, proving that it can be important to know which gene mutation you carry. Consult with your doctor when considering a genetic test to determine if you are eligible to participate in gene-based clinical trials.

PD GENEration: Mapping the Future of Parkinson’s Disease

This flagship study aims to provide free genetic testing and genetic counseling that will empower people with PD and their care team, improve Parkinson’s care and research and accelerate enrollment in clinical trials.

Through PD GENEration, we hope to ultimately offer free genetic testing and genetic counseling to 15,000 people with PD in the U.S., beginning with our goal of enrolling 600 participants during the pilot period. PD GENEration is available to people with a confirmed diagnosis of PD, regardless of age, through participating Centers of Excellence and Parkinson Study Group sites. To find out if your Center or site is participating, visit Parkinson.org/ PDGENEration.

For more information about genetics, visit Parkinson.org/Genetics or call our Helpline at 1-800-4PD-INFO (473-4636).

Parkinson’s disease (PD) affects approximately one million men and women in the United States, and more than 10 million people worldwide. Women have been shown to have a lower risk of developing PD, and research suggests that there are differences in the way that men and women experience Parkinson’s. Studies indicate that women diagnosed with PD report different symptoms, more often report side effects and changes in their symptoms throughout the day and receive lower-quality healthcare than men. This publication aims to highlight the historically unmet research and care needs of women with Parkinson’s disease, and elicit action in addressing these needs in future research and care.

Parkinson’s disease (PD) affects an estimated 10 million men and women worldwide. Women have been shown to have a lower risk of developing PD, and research suggests that there are differences in the way that men and women experience Parkinson’s. Studies indicate that women diagnosed with PD report different symptoms, more often report side effects and changes in their symptoms throughout the day (“fluctuations”) and receive lower quality healthcare than men.

What explains these differences? Based on the evidence so far, researchers can make some educated guesses. Some differences may have to do with biology—the way men’s and women’s bodies react to the disease or to therapies. Others may be due to lack of access to healthcare or to unintended differences in the way women are treated for PD compared to men.

Why the Lower Risk?

Studies conducted around the world, and across race, ethnic and age groups, support the finding that women overall have a lower risk of developing PD than men, but we still don’t know why. Environmental factors could explain this lower risk. It may be that women are less likely than men to be exposed to pesticides or heavy metals, or to sustain a head injury—all of which may increase a person’s PD risk.

Biological differences between women and men may also play a role. Estrogen, the female sex hormone, may protect the brain against PD, but little is known about its influence. If estrogen is preventative, it may only be helpful at certain levels or for a specific time.

What Are the Symptom Differences Between Men and Women?

Parkinson’s symptoms vary enormously from person to person. PD symptoms include motor symptoms, like tremor and stiffness, and nonmotor symptoms, like depression and fatigue.

Although women report experiencing some symptoms (including depression) more often than men, research to date has not conclusively shown whether symptoms affect women and men differently. This may be because symptoms vary as much among women as between women and men.

Are There Differences in Parkinson’s Treatment Between Men and Women?

All current treatment options (including medications, surgical options and exercise) address PD symptoms, but they do not slow down or stop the progression of PD. Levodopa, often prescribed as Sinemet, is considered the gold standard therapy for Parkinson’s movement symptoms. However, many people with PD experience changes in the effectiveness of the drug as the disease progresses. And some studies suggest that women are more likely than men to report these fluctuations earlier in the disease course and more frequently overall.

In particular, it seems that women are more likely to have involuntary movements called dyskinesias that occur when levodopa levels are highest in the blood. There are several factors that could be contributing to dyskinesia, including dosage, body weight and age of onset. Lower body weight can affect how medications build up in someone’s system. Lighter people sometimes need a smaller dose of medication to feel its effect. On average, women weigh less than men. If women and men are receiving similar doses, this may explain how levodopa levels are causing dyskinesias.

Physicians have also suggested that they find it harder to fine-tune Parkinson’s medications for women than for men. Women more often experience large swings in symptoms from even small changes in medications or schedules.

Deep brain stimulation (DBS) is an accepted surgical therapy for both men and women whose symptom fluctuations are difficult to control. Yet, even though women are reported to have greater improvement in quality of life after DBS, studies have shown that they are less likely than men to receive this therapy.

Are There Differences in Parkinson’s Care Between Men and Women?

Women with PD may face more barriers to quality healthcare and social support than men. Women are less likely than men to be cared for by a Parkinson’s specialist, such as a neurologist or movement disorder specialist, and are also less likely to have a care partner. On the other hand, women with Parkinson’s are more likely to do the following:

• Go to doctor’s appointments alone
• Use home healthcare
• Live in a skilled nursing facility

All these factors mean that women may not have access to adequate Parkinson’s care.

Conclusion

Research to date on women’s experience of PD underscores the need to focus more on this important part of the Parkinson’s community. Compared to men, women are diagnosed with PD less often, respond differently to current therapies, have less access to and lower use of expert care and are less socially supported. These combine so that women with PD have poorer quality of life than men. Studies that specifically address these issues are needed to improve the lives of all people affected by Parkinson’s.

Key Facts

• Women have a lower risk of developing Parkinson’s.
• There may be sex differences in PD symptoms, but the data are inconsistent.
• Small changes in medications or schedule can cause women to experience big changes in their symptoms, with dyskinesias being the most frequently reported side effect.
• Despite greater reported improvements to quality of life than men, women are less likely to receive deep brain stimulation (DBS).
• Women are less likely than men to be cared for by a PD specialist, neurologist or movement disorder specialist.
• Women with PD are accessing medical care for their Parkinson’s less than men.

As part of the Parkinson’s Foundation's Educational Book Series, Psychosis discusses just that: the causes, symptoms and treatments for hallucinations and delusions, as well as tips for caregivers of someone experiencing psychosis.

This book is only available digitally to view, download or print. It is also available in Kindle and audiobook formats.

Parkinson’s disease (PD) is often thought of in terms of its motor symptoms, such as slowness of movement, stiffness, and tremor. While l-dopa and dopaminergic drugs can help alleviate the motor symptoms of PD, patients are often also troubled by common non-motor symptoms such as fatigue, pain, sleep disturbances, constipation, urinary and sexual problems, and disturbed mood or cognition.

The good news is there are ways to address these problems, such as with other medications, visits to PD specialized therapists, exercise, dance, and other movement regimes. An awareness of non-motor symptoms and their connection to PD can help people with Parkinson’s find therapists, activities, and solutions that may alleviate the symptoms. In this podcast, Dr. Daniel Van Wamelen of King’s College in London discusses non-motor symptoms and ways to address them.

Released: October 8, 2019

Todavía hay mucho que no sabemos acerca de la enfermedad de Parkinson (EP). La investigación es clave para desbloquear sus causas y desarrollar tratamientos que cambien la vida, con el fin de encontrar una cura. Una manera en que las personas con EP pueden ayudar a los científicos a entender mejor la enfermedad es participando en la investigación.

Hay dos tipos de estudios clínicos: el estudio observacional y el ensayo clínico.

¿Qué es un estudio observacional?

Un estudio observacional es cuando los investigadores observan a las personas y tratan de averiguar qué factores afectan su salud y su probabilidad de desarrollar ciertas enfermedades como la EP. Por ejemplo, los investigadores podrían ver cómo diferentes estilos de vida afectan al Parkinson. En los estudios observacionales se mide o se encuesta a los participantes en lugar de administrarles tratamientos, como medicamentos. Los tipos de estudios observacionales incluyen:

• Los estudios de cohortes (o registro). Siguen a personas con una característica común a lo largo del tiempo.
• Los estudios de casos y controles. Se centran en las personas que han desarrollado una enfermedad y las comparan con un grupo de personas que no tienen la enfermedad.

¿Qué es un ensayo clínico?

Un ensayo clínico es un estudio de investigación con participantes humanos que propone responder preguntas específicas sobre posibles tratamientos médicos. Cuando los investigadores están desarrollando un tratamiento nuevo para una enfermedad, como un medicamento, cirugía, terapia o un dispositivo, se aseguran de que funcione a través de la realización de un ensayo clínico. Estos estudios ayudan a los investigadores y médicos a descubrir qué funciona y qué no, al tratar enfermedades como el Parkinson.

Tipos de ensayos clínicos de la EP:

• Terapéutico. Prueba la seguridad y la eficacia de una terapia potencial para la EP — con o sin fármacos — o una forma diferente de usar una terapia existente.
• Diagnóstico. Busca biomarcadores o un signo medible en el cuerpo que pueda diagnosticar la EP o rastrear su progresión.
• Genético. Ayuda a entender cómo afectan los genes a la EP.
• Preventivo. Busca encontrar formas de evitar que una persona desarrolle la EP.

Fases de los ensayos clínicos

Los tratamientos se someten a un riguroso proceso de ensayos clínicos antes de que la Administración de Alimentos y Medicamentos de los Estados Unidos (FDA, por sus siglas en inglés) pueda considerar su aprobación.

• Fase I. Pone a prueba un tratamiento potencial por primera vez en un grupo reducido de personas (con la enfermedad y sin ella) para evaluar la seguridad y la dosificación y para identificar los efectos secundarios.
• Fase II. Evalúa más a fondo el uso seguro de un tratamiento en un grupo reducido de personas de la población afectada y proporciona pruebas tempranas de su eficacia.
• Fase III. En un grupo más grande de personas, determina si el tratamiento ayuda a los participantes y si sus beneficios superan sus riesgos.
• Fase IV. Después de recibir la aprobación de la FDA, los investigadores recopilan y estudian información adicional sobre un tratamiento, incluidos los riesgos, los beneficios y la mejor manera de utilizarlo.

Riesgos de la participación en ensayos clínicos

• Es posible que el tratamiento del ensayo no funcione. Sin embargo, las investigaciones fallidas son importantes para descubrir más acerca de la EP.
• No recibir el tratamiento del estudio. Usted podría recibir un placebo (como una pastilla de azúcar) que permite a los investigadores comparar el grupo que recibe el tratamiento con un grupo que no lo recibe.
• Experimentar efectos secundarios no deseados. Estos pueden incluir efectos secundarios conocidos y nuevos que podrían aparecer durante el estudio. Pueden ser de naturaleza menor o grave.

Consentimiento informado

Es necesario que se firme un formulario de consentimiento informado sobre los riesgos y su papel en el estudio antes de participar.

Por qué participar en estudios clínicos

Su participación en estudios clínicos puede:

• Impulsar la prevención, los tratamientos y la cura del Parkinson.
• Darle acceso anticipado a tratamientos potencialmente benéficos que aún no están disponibles.
• Contribuir a la diversidad de participantes de la investigación.
• Ayudar incluso si no tiene Parkinson. Muchos ensayos están buscando “controles saludables” o personas que no tienen la EP.

¿Qué estudios son adecuados para usted?

Algunos estudios son tan sencillos como responder una encuesta, mientras que otros pueden incluir procedimientos o tratamientos. Es posible que desee pensar acerca de ciertos requisitos (frecuencia de visitas, duración de cada visita, tipos de pruebas, necesidad de viajar).

Asegúrese de hablar sobre su participación en un ensayo con:

• Su neurólogo. Puede ayudarle a evaluar un estudio específico y posiblemente recomendarle estudios adicionales.
• Su familia. Puede brinderle apoyo emocional.

Investigaciones en curso

Además de financiar becas de investigación, la iniciativa de investigación de la Parkinson’s Foundation incluye:

PD GENEration: Trazando el futuro de la enfermedad de Parkinson (PD GENEration: Mapping the Future of Parkinson’s Disease)

Este estudio nacional ofrece pruebas genéticas para genes relacionados con la EP y asesoramiento genético sin costo alguno para las personas con Parkinson. La participación puede ser presencial o desde casa mediante una cita de telemedicina. Para obtener más información y para inscribirse, visite Parkinson.org/PDGENEration.

Proyecto de Resultados del Parkinson (Parkinson’s Outcomes Project)

Es un estudio clínico entre más de 13,000 personas con la EP realizado en los Centros de Excelencia de la Parkinson’s Foundation. Lea más resultados en Parkinson.org/Outcomes.

Encuestas de la Parkinson’s Foundation

Esta iniciativa promueve la atención del Parkinson al comprender mejor las experiencias de las personas con EP y sus cuidadores y al compartir esta información con la comunidad. Hágase escuchar y regístrese en Parkinson.org/Surveys.

TOPAZ

En este estudio se evalúa si un medicamento, llamado zoledronato, puede prevenir fracturas óseas en personas con la EP. La participación se hace desde casa. Para obtener más información, visite TopazStudy.org.

Encontrar un estudio de Parkinson

• Clinicaltrials.gov Clinicaltrials.gov es una base de datos de estudios clínicos privados y públicos realizados en todo el mundo.
• Estudios de Investigación Clínica y Usted (Clinical Research Trials and You) de los Institutos Nacionales de la Salud (NIH, por sus siglas en inglés) es un recurso en línea para ayudar a las personas a aprender más acerca de los ensayos clínicos. Visite nih.gov/health/clinicaltrials.
• Encuentre lo último en la investigación de Parkinson y más información sobre cómo unirse a un estudio de investigación de la EP. Visite Parkinson.org/Research.

People who treat Parkinson’s disease (PD) and many people with PD know that there is not one typical form of the disease. One thing that may affect its symptoms and course is a person’s genetic make-up. The different genes that are risk factors for PD and the variations between them and even within the same gene may determine how the disease presents, progresses, and responds to treatments. With the aim of uncovering genes and mechanisms responsible for PD, the Parkinson’s Foundation initiated PD GENEration: Mapping the Future of Parkinson’s Disease, a study to look at the genes of 15,000 people with PD and correlate those findings with disease symptoms, progression, and response to treatments.

At the same time, participants in PD GENE will quickly get feedback on their genetic status that may allow them to enter clinical trials specific for the risk factors that they carry. The results will be much more comprehensive than what commercial genetic tests can provide, and it will all be free to the participants, including genetic counseling. In this podcast, neurologist and lead investigator, Dr. Roy Alcalay of Columbia University, a Parkinson’s Foundation Center of Excellence, and patient advocate Anne Hall give some background on the PD GENE genetics initiative.

Released: September 24, 2019

Parkinson’s disease (PD) may turn out to be not one disease but a group of similar conditions with different genetic risk factors, varying symptoms, and courses. Different genes may have variations between them or even variations within the same gene, with implications for symptoms, progression, and treatments. To help uncover key mechanisms responsible for PD and its progression, the Parkinson’s Foundation has launched PD GENEration: Mapping the Future of Parkinson’s Disease to study the genetic makeup of 15,000 people with the disease. The two main genes targeted in the study are carried by a minority of people with PD, but they may offer insights into mechanisms of the disease that operate in the larger population. In this podcast, Parkinson’s Foundation Chief Scientific Officer Dr. Jim Beck describes the goals of this Parkinson’s study, how genes affect the course of the disease, and ultimately, how the results of the study may empower people to take better control of their disease.

Released: August 13, 2019

Researchers and clinicians are learning that Parkinson’s disease (PD) is an umbrella term that covers similar but distinct variants of the disease that may result from differences in biology. Symptoms may be similar, but each person’s disease may have different features, rate of progression, needs, and treatments connected to the specific underlying cause. In this era of “personalized” medicine, a goal is to treat each person’s condition according to their unique disease. To do so, neurologists will need to be able to define and identify those differences (“biomarkers”) that will allow a truly personalized approach to treatment. A biomarker is a measurable indicator of a normal or abnormal bodily function. Examples are imaging such as MRI, chemicals in the blood or brain, brain wave patterns, sleep cycles, or even specific signs and symptoms.

Having biomarkers indicative of specific variants of the disease could help to design clinical trials to test therapies. It would allow researchers to include individuals with similar underlying biology when they test a potential new drug to be able to understand if it works for that form of PD. In a trial that included people falling under the umbrella term of “PD,” for example, researchers could see who benefited from the drug and then examine them to see what biomarkers they had in common. In this podcast, Dr. Anthony Lang, Director of the Edmond J. Safra Program in Parkinson’s Disease at the Toronto Western Hospital in Canada, discusses the need for biomarkers when searching for disease-modifying therapies – those treatments that can actually modify the course of PD and not just treat its symptoms. And he tells us why it is sometimes hard to tell the two apart.

Released: July 30, 2019