Published online Mar 22, 2015. doi: 10.5498/wjp.v5.i1.138
Peer-review started: July 27, 2014
First decision: August 14, 2014
Revised: September 7, 2014
Accepted: November 17, 2014
Article in press: November 19, 2014
Published online: March 22, 2015
Processing time: 239 Days and 8.3 Hours
AIM: To compare adherence, response, and remission with light treatment in African-American and Caucasian patients with Seasonal Affective Disorder.
METHODS: Seventy-eight study participants, age range 18-64 (51 African-Americans and 27 Caucasians) recruited from the Greater Baltimore Metropolitan area, with diagnoses of recurrent mood disorder with seasonal pattern, and confirmed by a Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders-IV, were enrolled in an open label study of daily bright light treatment. The trial lasted 6 wk with flexible dosing of light starting with 10000 lux bright light for 60 min daily in the morning. At the end of six weeks there were 65 completers. Three patients had Bipolar II disorder and the remainder had Major depressive disorder. Outcome measures were remission (score ≤ 8) and response (50% reduction) in symptoms on the Structured Interview Guide for the Hamilton Rating Scale for Depression (SIGH-SAD) as well as symptomatic improvement on SIGH-SAD and Beck Depression Inventory-II. Adherence was measured using participant daily log. Participant groups were compared using t-tests, chi square, linear and logistic regressions.
RESULTS: The study did not find any significant group difference between African-Americans and their Caucasian counterparts in adherence with light treatment as well as in symptomatic improvement. While symptomatic improvement and rate of treatment response were not different between the two groups, African-Americans, after adjustment for age, gender and adherence, achieved a significantly lower remission rate (African-Americans 46.3%; Caucasians 75%; P = 0.02).
CONCLUSION: This is the first study of light treatment in African-Americans, continuing our previous work reporting a similar frequency but a lower awareness of SAD and its treatment in African-Americans. Similar rates of adherence, symptomatic improvement and treatment response suggest that light treatment is a feasible, acceptable, and beneficial treatment for SAD in African-American patients. These results should lead to intensifying education initiatives to increase awareness of SAD and its treatment in African-American communities to increased SAD treatment engagement. In African-American vs Caucasian SAD patients a remission gap was identified, as reported before with antidepressant medications for non-seasonal depression, demanding sustained efforts to investigate and then address its causes.
Core tip: Consistent findings suggesting that light treatment is safe and effective for Seasonal affective disorder (SAD) emerged from prior research on samples with highly predominant Caucasian representation. As there are no previous reports on light treatment for SAD in African-Americans, we undertook the first study comparing effects of light treatment in African-American and Caucasian patients with Seasonal Affective Disorder. After six weeks of treatment, improvement in depression scores, response (50% improvement in symptoms), and adherence to treatment were similar between the two racial groups. However, the remission rates were significantly lower in African-Americans. Thus additional research is needed to better understand and ultimately reduce the remission gap between Caucasian and African-American patients with SAD.