Table 1 Inclusion and exclusion criteria

Minimum age of 18 years

Any diagnosis of a disease that may affect the central nervous system (brain condition, traumatic brain injury, dementia, etc.)

DSM-5 diagnosis of Major Depression or persistent depressive disorder, mild or moderate depression expressed as a score lower than 14 in the Patient Health Questionnaire (PHQ-9)

Other psychiatric diagnoses or acute psychiatric illness (substance dependence or abuse, history of schizophrenia or other psychotic disorders, eating disorders, etc.), except for anxiety disorder or personality disorders

Ability to understand oral and written Spanish

Any medical, infectious or degenerative disease that may affect mood

Willingness to participate in the study and signing informed consent

Presence of delusional ideas or hallucinations whether consistent or not with mood

Duration of depressive symptoms 2 months or more

Suicide risk

Diagnosis of one of the following two conditions:

- Type 2 Diabetes (Diagnosis according to criteria of the American Diabetes Association, ADA)

- Lower back pain (Diagnosis of non-specific chronic low back pain according to the definition established by the CPG COST B-13 with a duration of at least 6 months)

Possession of and ability to use a computer, an Internet connection and a mobile phone