Table 1 Keywords employed to search MDD related publications in PubMed for MK4MDD

Keywords category

Specific keywords used in PubMed search

Covered data level

Keywords targeting the first three research levels

‘gene’, ‘epigenetic’, ‘protein’, ‘molecule’, ‘molecular’, ‘signaling’, ‘pathway’, ‘cell’, ‘cellular’, ‘neural’, ‘neuron’, ‘neurotransmitter’, ‘association’, ‘linkage’, ‘methylation’, ‘methylate’, ’histone’, ‘modify’, ‘modification’, ‘chromatin  remodeling’

Genetic/epigenetic locus

Protein and other molecule

Cell and molecular pathway

Keywords for neurobiological system

‘glutamate’, ‘γ-aminobutyric acid’, ‘monoamine’, ‘dopamine’, ‘norepinephrine’, ‘noradrenaline’, ‘epinephrine’, ‘5-HT’, ‘acetylcholine’,  ‘nitric oxide’, ‘immune system’, ‘neuroendocrine’, , ‘hypothalamic-pituitary-adrenal axis’, ‘HPA’, ‘hypothalamic-pituitary-thyroid axis’, ‘HPT’, ‘hypothalamic-pituitary-gonadal axis’, ‘hypothalamic-pituitary gland-growth hormone axis’, ‘HPGH’,

Genetic/epigenetic locus

Protein and other molecule

Cell and molecular pathway

Neural system

Symptomatic keywords

‘depressed mood’, ‘insomnia’, ‘hypersomnia’, ‘anhedonia’, ‘psychomotor retardation’, ‘low energy’, ‘fatigue’, ‘agitation’, ‘irritability’, ‘suicide intent’, ‘low self esteem’, ‘hopeless’, ‘worthlessness’, ‘guilt’, ‘decreased appetite’, ‘increased appetite’, ‘weight loss’, ‘weight gain’, ‘appetite’, ‘cognitive dysfunction’, ‘impaired memory’, ‘impaired concentrate’, ‘impaired executive function’

Cognition and behavior

Symptoms

Methodological keywords

‘functional magnetic resonance’, ‘functional magnetic resonance imaging’, ‘fMRI’, ‘magnetic resonance imaging’, ‘magnetic resonance images’, ‘MRI’, ‘positron emission tomography’, ‘single photon emission tomography’, ‘PET’, ‘single photon emission computed tomography’, ‘SPECT’, ‘magnetic resonance spectroscopy’, ‘diffusion tensor imaging’, ‘electroencephalogram’, ‘EEG’, ‘event-related potential’, ‘event-related potentials’, ‘ERPs’, ‘ERP’, ‘magnetoencephalography’, ‘MEG’, ‘postmortem’, ‘eye-tarcking’, ‘eye movement’, ‘neuropsychological test’

Neural system

Cognition and behavior