Effects of royal jelly on improvement of brain function

INTERVENTION: Test material: Dried royal jelly powder Duration: 8 weeks Dose: Daily 1000mg (equivalent to 3000 mg of fresh Royal Jelly) Test material: Placebo Duration: 8 weeks Dose: Casein 500mg, carbohydrate 90mg, lipid 24mg (equivalent amounts of protein, carbohydrate, and lipid contained in 3000 mg of royal jelly) CONDITION: Psychiatric disorders PRIMARY OUTCOME: Survey 8 weeks after administration; Electroencephalography (event‐related potential P3a & P3b, mismatch negativity, evoked gamma rhythms, and auditory evoked potentials) SECONDARY OUTCOME: Questionnaires (BDI, PANAS); Evaluation of cognitive function (attention network test, word frequency test, digit symbol substitution test, verbal learning test, effort based decision making test); MRS (measurement of glutathione, NAA, NAAG, glutamate, glutamine); Biochemical analysis (sleep‐wake cycle‐related hormones, inflammatory factors, stress‐related hormones) INCLUSION CRITERIA: (1) Men and women aged 30 to 75 years old (2) BMI of more than 25