Seasonal difference in brain serotonin transporter binding predicts symptom severity in patients with seasonal affective disorder

TY - JOUR

T1 - Seasonal difference in brain serotonin transporter binding predicts symptom severity in patients with seasonal affective disorder

AU - Mc Mahon, Brenda

AU - Andersen, Sofie B.

AU - Madsen, Martin K.

AU - Hjordt, Liv V.

AU - Pedersen, Ida Hageman

AU - Dam, Henrik

AU - Svarer, Claus

AU - da Cunha-Bang, Sofi

AU - Baare, William

AU - Madsen, Jacob

AU - Hasholt, Lis

AU - Holst, Klaus

AU - Frokjaer, Vibe G.

AU - Knudsen, Gitte M.

PY - 2016/5/1

Y1 - 2016/5/1

N2 - Cross-sectional neuroimaging studies in non-depressed individuals have demonstrated an inverse relationship between daylight minutes and cerebral serotonin transporter; this relationship is modified by serotonin-transporter-linked polymorphic region short allele carrier status. We here present data from the first longitudinal investigation of seasonal serotonin transporter fluctuations in both patients with seasonal affective disorder and in healthy individuals. Eighty 11 C-DASB positron emission tomography scans were conducted to quantify cerebral serotonin transporter binding; 23 healthy controls with low seasonality scores and 17 patients diagnosed with seasonal affective disorder were scanned in both summer and winter to investigate differences in cerebral serotonin transporter binding across groups and across seasons. The two groups had similar cerebral serotonin transporter binding in the summer but in their symptomatic phase during winter, patients with seasonal affective disorder had higher serotonin transporter than the healthy control subjects (P = 0.01). Compared to the healthy controls, patients with seasonal affective disorder changed their serotonin transporter significantly less between summer and winter (P<0.001). Further, the change in serotonin transporter was sex-(P = 0.02) and genotype-(P = 0.04) dependent. In the patients with seasonal affective disorder, the seasonal change in serotonin transporter binding was positively associated with change in depressive symptom severity, as indexed by Hamilton Rating Scale for Depression - Seasonal Affective Disorder version scores (P = 0.01). Our findings suggest that the development of depressive symptoms in winter is associated with a failure to downregulate serotonin transporter levels appropriately during exposure to the environmental stress of winter, especially in individuals with high predisposition to affective disorders.

AB - Cross-sectional neuroimaging studies in non-depressed individuals have demonstrated an inverse relationship between daylight minutes and cerebral serotonin transporter; this relationship is modified by serotonin-transporter-linked polymorphic region short allele carrier status. We here present data from the first longitudinal investigation of seasonal serotonin transporter fluctuations in both patients with seasonal affective disorder and in healthy individuals. Eighty 11 C-DASB positron emission tomography scans were conducted to quantify cerebral serotonin transporter binding; 23 healthy controls with low seasonality scores and 17 patients diagnosed with seasonal affective disorder were scanned in both summer and winter to investigate differences in cerebral serotonin transporter binding across groups and across seasons. The two groups had similar cerebral serotonin transporter binding in the summer but in their symptomatic phase during winter, patients with seasonal affective disorder had higher serotonin transporter than the healthy control subjects (P = 0.01). Compared to the healthy controls, patients with seasonal affective disorder changed their serotonin transporter significantly less between summer and winter (P<0.001). Further, the change in serotonin transporter was sex-(P = 0.02) and genotype-(P = 0.04) dependent. In the patients with seasonal affective disorder, the seasonal change in serotonin transporter binding was positively associated with change in depressive symptom severity, as indexed by Hamilton Rating Scale for Depression - Seasonal Affective Disorder version scores (P = 0.01). Our findings suggest that the development of depressive symptoms in winter is associated with a failure to downregulate serotonin transporter levels appropriately during exposure to the environmental stress of winter, especially in individuals with high predisposition to affective disorders.

KW - seasonal affective disorder

KW - serotonin

KW - serotonin transporter

KW - serotonin transporter linked polymorphic region

KW - PET

U2 - 10.1093/brain/aww043

DO - 10.1093/brain/aww043

M3 - Journal article

C2 - 26994750

SN - 0006-8950

VL - 139

SP - 1605

EP - 1614

JO - Brain

JF - Brain

ER -