Retrospective Observational Study of Blood-based Biomarkers in the Diagnosis and Monitoring of Patients With a Neurodegenerative Disease or Mental Disorder

Inclusion Criteria: * Age\>18 and donation of blood, * full clinical and psychological assessment * Available neuroimaging is optional as not all patients are suitable. * Age and sex-matched unaffected volunteers without a MD or ND diagnosis are used as controls. * Unaffected controls are usually spouses or children of patients that are informed about our studies at each clinical site. Exclusion Criteria: * Lack of neuropsychological data, * anticoagulant treatment such as acenocoumarol, heparin, warfarin, dabigatran, rivaroxaban, apixaban, drug abuse in the last year, * medical history of cancer affecting the central nervous system that has not been in complete remission for 5 years or longer, * the patient has received potentially neurotoxic chemotherapy and/or patient has received cranial radiotherapy. * Clinical diagnosis of Alzheimer's disease where pathophysiological markers (measured in CSF or plasma) are inconsistent with Alzheimer's disease pathophysiology. * Cognitively healthy volunteers where pathophysiological markers (measured in CSF or plasma) are consistent with Alzheimer's disease or other neurodegenerative pathophysiology.