Apathy, anxiety and depression are among the psychiatric disorders that affect more than half of Parkinsonian patients. These pathologies were addressed at the III Symposium on "Cognitive disorders in Parkinson's disease" held at the research center Applied Medicine (CIMA) of the University of Navarra. Neurologists from several countries attended this annual congress organized by Dr. María Cruz Rodríguez-Oroz and Dr. José Obeso, from CIMA and the University of Navarra. Clínica Universidad de Navarratogether with Lundbeck Laboratories. 

The impulse control disorder associated with Parkinson's, and of increasing frequency in the specialist's enquiry , was also discussed. This is an additional psychiatric manifestation of the disease that is sample in gambling or pathological shopping, overeating and hypersexuality, among others.

Paul Krack, a neurologist at Joseph Fourier University in Grenoble, recalled that Parkinson's "is much more than a disease linked to movement problems". His research focuses on the relationship between the amount of dopamine administered to patients and the neuropsychiatric symptoms of the disease, linked to the dopaminergic system. These have been categorized into hyperdopaminergic behaviors, which are impulse control disorders, and hypodopaminergic behaviors, which encompass apathy, anxiety and depression.

"In treatments with deep brain stimulation, a subject surgery in which tiny electrodes are implanted in the brain, patients experience significant motor improvement that allows them to reduce their medication. Symptoms such as apathy or depression then become apparent. This opens a window to understand depression and other motivation-related states in Parkinson's disease," says Dr. Krack. In this sense, he advocates treating patients from both motor and non-motor points of view, combining surgery and pharmacological treatment and balancing the neuropsychiatric symptoms of the disease.

The use of surgery is not a risk factor for apathy or depression.

Paul Krack's study presented at the symposium focuses on apathy, depression and anxiety associated with Parkinson's disease. "It was thought that apathy appeared as a side effect of surgery, but we have shown that this is not the case, but is due to the reduction of dopaminergic medication, the manager of this manifestation," he explained. He also pointed out that in order to improve the motor symptoms, they treated the patient with deep brain stimulation and withdrew the dopamine medication, since his motor problems and tremors disappeared. "There is what we specialists call a second honeymoon without medication, the first one they experience when the medical treatment with dopamine begins. After about 4 months, we observe that the non-motor symptoms of the disease are unmasked. This process takes a while: apathy, depression and anxiety do not appear in three days." Paul Krack finds at this point a challenge for the research: "The brain has a great plasticity and the effects of drugs last for months even after withdrawal of the medication. Taking this into account in Parkinson's disease is an important advance."

At the conclusion of the scientific meeting , Dr. Mª Cruz Rodríguez-Oroz, neurologist at CIMA and Clínica Universidad de Navarra, explained that "this symposium has focused on the neuropsychiatric aspects of patients with Parkinson's disease, whose pathophysiology is less well known, but which has recently been related to the dopaminergic system. In this sense, the use of surgery in Parkinson's disease is not a risk factor for apathy or depression; rather, with proper drug management after surgical treatment, the appearance of these disorders can be avoided".