Welcome to the site.
I am Dr. Kaushik and i believe i can help you with your question.
Well light therapy is usually and to some extent exclusively used for a condition called as SAD ( Seasonal Affective Disorder) which has been colloquially termed as Winter Depression as it is most commonly seen in winters when the days are short and sunlight is in deficit thereby causing some vulnerable lot to slip into a depressive cognition. So comes the light therapy to help such patients out and overcome the depressed state.
However light therapy is not usually recommended for Bipolar disorder and medication still remains the best ploy to counter the Bipolar symptoms including depression.
No light therapy is not associated with precipitation of a manic episode.
I hope this helps.
Wish you all the best.
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