Effect of intranasal oxytocin on social approach in patients with social phobia and healthy control

INTERVENTION: Intervention 1: The participants of arm 1 (control subjects) will be examined in two sessions, 2h each, spaced 4 weeks apart. In session 1 they receive a dose of 26 IU oxytocin (Syntocinon®), administered intranasally. In session 2 the equivalent amount of a placebo nasal spray will be administered. Intervention 2: The participants of arm 2 (control subjects) will be examined in two sessions, 2h each, spaced 4 weeks apart. In session 1 they receive a dose of 26 IU placebo (Syntocinon®), administered intranasally. In session 2 the equivalent amount of oxytocin (Syntocinon®) nasal spray will be administered. Intervention 3: The participants of arm 3 (patients) will be examined in two sessions, 2h each, spaced 4 weeks apart. In session 1 they receive a dose of 26 IU oxytocin (Syntocinon®), administered intranasally. In session 2 the equivalent amount of a placebo nasal spray will be administered. Intervention 4: The participants of arm 4 (patients) will be examined in two sessions, 2h each, spaced 4 weeks apart. In session 1 they receive a dose of 26 IU placebo (Syntocinon®), administered intranasally. In session 2 the equivalent amount of oxytocin (Syntocinon®) nasal spray will be administered. CONDITION: F40.1 ‐ Social phobias PRIMARY OUTCOME: The BOLD response quantified with fMRI (in 3T MRI scanner) after application of oxytocin/placebo. SECONDARY OUTCOME: Hormone serum levels of oxytocin, progesterone, testosterone, estradiol from blood taken at several time points in the course of the study. INCLUSION CRITERIA: inclusion criteria for control group: Age between 18 and 45, Full capacity to understand and execute instructions of the study, signed form of consent. inclusion criteria for patient group: Age between 18 and 45, diagnosis of social phobia (according to ICD‐10), The screening methods applied are the Social Phobia Inventory (SPIN, patient assessment) using a minimal score of 19 and the Liebowitz Anxiety Scale (LAS, assessment by interviewer, minimal score of 55 points), Full capacity to understand and execute instructions of the study, signed form of consent.