[1] Dept Clin Neurosci, Sect Psychiat, Huddinge, Sweden
[2] Karolinska Inst, Stockholm, Sweden
[3] CNR, Inst Cognit Sci & Technol, Rome, Italy
[4] Karolinska Hosp, Dept Nucl Med, S-10401 Stockholm, Sweden
[5] St Gorans Univ Hosp, Karolinska Inst, Sect Psychiat, Dept Clin Neurosci, Stockholm, Sweden
[6] Karolinska Inst, Div Social Med, Dept Publ Hlth Sci, Stockholm, Sweden