Questionnaire
On the blood sample taking-day, the subjects were asked to fill in a short questionnaire. They were asked to estimate how many times they had had an acute illness, including an infection, in the past month and the past 6 months (ordinal variables acute illness in last month and acute illness in past 6 months ), how many chronic health problems they had been treated for in the past month (chronic problems treated now ), and how many other chronic health problems they suffer, including untreated problems (chronic problems all ), how many kinds of drugs prescribed by a medical doctor they were currently taking, how well they felt physically on the blood sample taking-day (bad physical health today , 6-points scale 1: excellently, 6: very badly), how often they suffer from headaches(1: never, 2: exceptionally, 3: once a month, 4: once a week, 5: daily), and whether they had been diagnosed with tension headaches ormigraines (0: no, 1: yes). In different questionnaires distributed electronically on another day, they were asked how often they suffer from allergies , skin disorders (nonallergic),circulatory system disorders (heart or vascular), digestive tract disorders (ulcer, pancreas, etc.), orthopedic disorders (backache, joints ache, etc.), neurological disorders , headaches ( headaches 2) , other physical pains , other chronic or recurrentphysical problems , and how frequently they are tired . To answer all these questions, participants should use six-points scales (1: never, 2: maximally once a year, 3: several times a year, maximally once a month, 4: several times a month, maximally once a week, 5: two or more times a week, 6: daily or several times a day). They were also asked whether they suffer from metabolic disorders (diabetes etc.) (1: definitively no, 2: more likely no, 3: more likely yes, 4: definitively yes), what their blood pressure is (1: I do not know – coded as β€œND”, 2: very low, 3: rather low, 4: normal, 5: rather high, 6: very high), how often they are tired immediatelyafter returning from work (or school) (1: never, 2: rarely, 3: sometimes, 4: often, 5: nearly always, 6: always), how often they are tired after several hours-travel by train , (the same scale), and how often they are tired after several hours-travel by bus , (the same scale). Besides that, they were asked how often they suffer from common infectious diseases like influenza or a similar viral or bacterial disease (1: never, 2: maximally once a year, 3: several times a year, maximally once a month, 4: several times a month, maximally once a week, 5: two or more times a week), how often they attend medical doctors (not dentist and not for prevention) (1: never, 2: maximally once a year, 3: several times a year, maximally once a month, 4: several times a month, maximally once a week, 5: two or more times a week), how many times they had usedantibiotics in the last year (1: never, 2: once, 3: twice, 4: three times, 5: four times 6: five or more times), how many times they had used antibiotics in the last 3 years (the same scale), how many times they had spent more than a week in a hospital in the last year (the same scale), how many times they had spent more than a week in a hospital in the past 5 years (the same scale), and how long they expect to live (life expectancy 1: more than 99 years. 2: 90-99 years, 3: 80-90 years, 4: 70-79 years, 5: 60-69 years, 6: less than 60 years). Physical health problems score was computed as mean Z-score from these 30 physical health-related variables.
In the first questionnaire (before blood taking), participants were asked to rate how well they feel mentally today (bad mental health today , 6-points scale anchored with 1: excellent, 6: very bad). In the following electronic questionnaires, they were asked how many specificlearning disabilities (e.g. dyslexia or dysgraphia) they have, whether they suffer from phobias (anchored with 1: no, 6: yes, with many or intensive), from depression (1: never, 2 maximally once a year, 3: several times a year, maximally once a month, 4: several times a month, maximally once a week, 5: two or more times a week, 6: daily or several times a day), and from other mental health problems (the same scale). They were also asked whether they feelmentally bad today (anchored with 1: definitively no, 6: definitively yes), and whether they feel mentally badly usually(the same 6-point scale). Separately, participants also completed a standard NEO-PI-R questionnaire with its neuroticism subscalesanxiousness and depressiveness(Costa & McCrae, 1992). Mental health problems score was computed as a mean Z-score from these 9 mental health-related variables.