Retinoic Acid Homeostasis in Neuropsychiatric Diseases

MDD-Group Inclusion Criteria: * depressive episode in the context of unipolar major depression * at least 18 points or more on the BDI and HAMD-17 Exclusion Criteria: * additional or comorbid axis-I or axis-II disorder * current history of any neurological or other serious medical condition * any psychopharmacological treatment or substance use within the last two weeks or 5 half-lives (whichever is longer) of the respective substance * any oral or topical application of retinoid-containing preparations within the last 3 months AD-Group Inclusion Criteria: * diagnosed AD Exclusion Criteria: * any other neurodegenerative disorder * any oral or topical application of retinoid-containing preparations within the last 3 months Schizophrenia-Group Inclusion Criteria: * subjects with schizophrenia * intended therapy with clozapine, olanzapine or aripiprazole * BMI: 18 - 29,9 kg/m2 Exclusion Criteria: * presence of diabetes or pathological glucose tolerance * presence of and chronic inflammatory disease * any psychopharmacological treatment of clozapine, olanzapine or aripiprazole within the last 3 months * any oral or topical application of retinoid-containing preparations within the last 3 months Alcoholism-Group Inclusion Criteria: * subjects with alcoholism who either still consume alcohol or are abstinent for at least 4 weeks Exclusion Criteria: * any oral or topical application of retinoid-containing preparations within the last 3 months * current history of …