Association of translocator protein total distribution volume with duration of untreated major depressive disorder: a cross-sectional study

We examined the relationship of translocator protein (TSPO) total distribution volume (VT), a marker of microglial activation, with duration of untreated major depressive disorder, and with total illness duration and antidepressant exposure. Methods In this cross-sectional study, we recruited participants aged 18–75 years from the Toronto area and the Centre for Addiction and Mental Health (Toronto, ON, Canada). Participants either had major depressive episodes secondary to major depressive disorder or were healthy, as confirmed with a structured clinical interview and consultation with a study psychiatrist. To be enrolled, participants with major depressive episodes had to score a minimum of 17 on the 17-item Hamilton Depression Rating Scale, and had to be medication free or taking a stable dose of medication for at least 4 weeks before PET scanning. Eligible participants were non-smokers; had no history of or concurrent alcohol or substance dependence, neurological illness, autoimmune disorder, or severe medical problems; and were free from acute medical illnesses for the previous 2 weeks before PET scanning. Participants were excluded if they had used brain stimulation treatments within the 6 months before scanning, had used anti-inflammatory drugs lasting at least 1 week within the past month, were taking hormone replacement therapy, had psychotic symptoms, had bipolar disorder (type I or II) or borderline antisocial personality disorder, or were pregnant or breastfeed...
Source: The Lancet Psychiatry - Category: Psychiatry Source Type: research