Fig. 3: MAO-A VT decrease from fall/winter to spring/summer in HC.
From: Brain monoamine oxidase A in seasonal affective disorder and treatment with bright light therapy
MAO-A VT decreased in HC from fall/winter (PET1, before BLT/placebo) to spring/summer (F1, 187.84 = 4.79, p = 0.030), while no change was shown in SAD. Though higher MAO-A VT in HC in fall/winter compared to spring/summer appears contrary to the hyposerotonergic hypothesis of depression, it may be reflective of results from previous studies showing that MAO-A levels are dependent on substrate availability31. Higher MAO-A VT in fall/winter may therefore be secondary to other mechanisms that increase serotonin, hereby preventing development of SAD. Bars denote mean MAO-A VT for HC (blue, BLT and placebo pooled) and SAD (red, BLT and placebo pooled), brackets denote standard error. Illustrated MAO-A VT is averaged for all ROIs. *p ≤ 0.050. MAO-A VT: monoamine oxidase A distribution volume, BLT: bright light therapy, SAD: seasonal affective disorder, HC: healthy controls
