For those interested participants, our services coordinator, co-investigator or principal investigator will interview and explain the study in detail and obtain your consent. After signed the consent, the participant should complete the Neuro-QoL (Quality of Life in Neurological Disorders) questionnaire first, either on-site at CUHK Brain Health Centre located at Tsim Sha Tsui in Hong Kong, PWH or community centre. The questions in the questionnaire focus on the following: ability to participate in social roles, emotional and behavioral dyscontrol, fatigue, lower extremity function, stigma, upper extremity function, positive affect and well-being, satisfaction with social roles, cognitive function, anxiety and depression. These questions enable us to get a full picture of the participant's health. Participants in Green and yellow groups will receive this standard battery of questions. However, participants in Red group may receive an additional subset of questions based on their clinical diagnosis. Once again, all subjects are asked to complete this questionnaire for clinical evaluation purposes, regardless of whether or not they decide to participate in this study.

When the participant is willing to join the study, an evaluation would be scheduled. At that visit, our physician and/or study coordinator will review the participant's medical history, current concerns, and responses to the questionnaires. Diagnostic and therapeutic recommendations may be offered, as warranted. The investigator or physician will determine whether a follow-up clinic visit is warranted. Depending on the physician's recommendations, the participant will either participate in a research phone call in approximately 6 months, or will be scheduled for in person research follow up. In addition to the phone call or clinic visit, and will also receive an identical questionnaire to the first one by e-mail, by phone, or in person. Follow-up over time will continue (either in-person or over the phone) using the same questionnaires at approximately 6-month intervals. During follow-up, participant will be screened for new signs, symptoms and diagnoses of neurological and/or psychiatric disorders, in order to correlate these outcomes with risk factors captured using the procedures described above.

The proposed study does not involve formulating new diagnoses or directly offering treatment for neurological and/or psychiatric conditions. All patients admitted to PWH or other medical institutes will be treated according to the standard care at the corresponding institution, regardless of their decision to participate in this repository. Should results from this study lead to discovery of one or more factors associated with development of brain disease, the principal investigators, co-investigators, or study coordinator in the CUHK Brain Health Centre will inform, counsel and offer diagnostic and/or therapeutic recommendations to participants accordingly. The participants may be referred to relevant departments for follow-up clinical visits and may also be invited to participate in sister research projects at PWH/CUHK that have obtained ethics approval; if the participants are interested in any sister projects, they may be offered tests as the study procedures of these projects, including but not limited to blood tests, genetic tests, retinal imaging and brain imaging exams.

Our study aims to follow longitudinally individuals with or at risk for neurological and psychiatric disease, regardless of gender or sexual orientation. The investigators focus on enrolling adults as the vast majority of the neurological and psychiatric conditions of interest are diagnosed well into adulthood; indeed, most are age-related and particularly frequent among individuals in the fifth decade of life and beyond. Our study uniquely welcomes even individuals who are healthy from a brain standpoint, and offers them an opportunity to increase our scientific understanding of the early transition from normal to pathological brain functioning. As a result, the entire population as a whole stand to potentially benefit from the outcomes of the proposed research.