Appetitive Symptoms, Fluoxetine, and Light Therapy: Predicting Treatment Response for Nonseasonal Major Depression

green and white pill
green and white pill
Researchers examined whether more severe appetitive symptoms predicted a positive response to light therapy.

For patients with nonseasonal major depressive disorder (MDD), there is no significant association between appetitive symptoms and light therapy on its own, according to a recent study published in the Journal of Clinical Psychiatry. However, initial findings suggest that fluoxetine with or without light therapy might be an effective treatment option for those with more severe appetitive symptoms.

To determine whether more severe appetitive symptoms predict a positive response to light therapy, researchers conducted a randomized, double-blind study in which 122 patients (average age 36.8) diagnosed with nonseasonal MDD received 1 of 4 treatment conditions: active light therapy plus 20 mg/d of fluoxetine, active light plus a placebo pill, 20 mg/d of fluoxetine plus inactive light therapy, or placebo pill plus inactive light therapy. All 4 groups received the same light box, but only for the active therapy groups was the box’s negative ion generator turned on.

There were no significant differences between groups in baseline depression scores, appetitive symptom scores, or body mass index.

For participants in the placebo/inactive light group, more appetitive symptoms at baseline predicted a lesser decrease in depression scores at 8 weeks (r =-.37). In contrast, those in the active treatment groups demonstrated that more appetitive symptoms at baseline predicted a greater decrease (only fluoxetine group: r =.23; only light therapy group: r =.11; combination group: r =.32).

Researchers noted multiple limitations to their study, including an inability to distinguish subgroup effects appropriately because of the small sample size.

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Because of such limitations, they concluded that their findings should be considered purely preliminary, adding, “In contrast to studies in seasonal affective disorder, the current results do not support a clear benefit of light therapy alone in patients with nonseasonal MDD and more appetitive symptoms.”

Disclosures: The researchers reported numerous affiliations with institutions including but not limited to: Shire Canada, Bristol-Myers Squibb, Lundbeck, Lundbeck Institute, Pfizer, AstraZeneca, Eli Lilly, Mochida, Otsuka, Servier, Takeda, GlaxoSmithKline, Johnson & Johnson, Novartis, Abbot, Servier, and Wyeth. Please see the published study for a full list of disclosures.


Levitan R, Levitt AJ, Michalak EE, et al. Appetitive symptoms differentially predict treatment response to fluoxetine, light, and placebo in nonseasonal major depression. J Clin Psychiatry. 2018;79:17m11856.