Light-Therapy in the Treatment of the Acute Phase of the Bipolar Type II Depression

Inclusion Criteria: * Bipolar type II disorder, depressive phase meeting DSM-IV criteria as per the SCID interview * Hamilton Depression Rating Scale 21 items (HAMD-21) ≥ 17 and a Montgomery Asberg rating Scale (MADRS) ≥ 15 for at least 2 weeks and the episode has begun during the month of september or a later month * Able to give their consent and willingness to participate to the study Exclusion Criteria: * Other psychiatric condition, organic brain disorder, unstable and/or untreated medical condition such as hypothyroidism, diabetes, cardiac condition, hypertension * Deficit in vitamin B12 or folate * Sub-syndromic hypomania symptoms as per a Young Mania Rating Scale (YMRS) score ≥ 4 * History of manic or hypomanic switch when exposed to bright light or during prolonged exposure to the sun during previous depressive phases * Pregnancy or absence of a contraceptive treatment * History of light-induced migraine or epilepsy * Marked suicidal ideation * Retinal blindness or severe cataract * Glaucoma, retinal diseases of the eye * Alcohol or drug abuse * Known skin sensitivity to sunlight, especially in patients receiving photosensitizing drugs such as lithium or phenothiazines * Past history of light therapy