Atypical Parkinson Disease

The goal of this clinical trial is to evaluate whether psilocybin therapy can effectively treat depression and psychological distress in adult patients with COPD, ALS, MS, or APD who have at least 6 months life expectancy. The main questions it aims to answer are: * Can psilocybin therapy safely reduce depressive symptoms compared to low-dose control? * Will the therapeutic effects be rapid and sustained over a 6-month period? Researchers will compare patients receiving two escalating doses of psilocybin (15mg followed by 25mg) against those receiving two low doses (1mg) to see if the higher doses lead to greater improvements in depression, anxiety, demoralization, and quality of life. Participants will: * Attend three preparation sessions with psychotherapists (1-2 hours each) * Undergo two supervised psilocybin dosing sessions (6-8 hours each) * Complete five integration therapy sessions following the dosing sessions * Participate in follow-up assessments at 6 weeks, 3 months, and 6 months * Have access to a digital care platform and peer support groups during the 6-month follow-up period * Optional: Control group participants may receive one high-dose psilocybin session (25mg) after the initial study period

Every-day life means being part of a complex environment and performing complex tasks that usually involve a combination of motor and cognitive skills. However, the process of aging or the sequelae of neurological diseases such as atypical Parkinson's disease (APD) compromises motor-cognitive interaction necessary for an independent lifestyle. While motor-cognitive performance has been identified as an important goal for sustained health across different clinical populations, little is known about underlying brain function leading to these difficulties and how to best target these motor-cognitive difficulties in the context of rehabilitation and exercise interventions. The challenge of improving treatments of motor-cognitive difficulties (such as dual-tasking and navigation) is daunting, and an important step is arriving at a method that accurately portrays these impairments in an ecologically valid state. The investigators aim therefore to explore brain function during complex walking in healthy and APD by investigating the effects of age and neurological disease on motor-cognitive performance and its neural correlates during three conditions of complex walking (dual-task walking, navigation and a combination of both) using non-invasive measures of brain activity (functional near infrared spectrometry, fNIRS) and advanced gait analysis in real time in older healthy adults and people with APD.

The purpose of this study is to investigate whether speed-dependent measures of gait can be identified in patients with neurological conditions that affect gait, particularly in subjects with parkinsonian disorders.