It could be the problem or only part of the problem. If the plant was already struggling to keep up with its water needs, moving it to a brighter location could easily exacerbate the problem. If it was an issue of watering too infrequently, that could be easily solved, but if it's due to over-watering or an excess of soluble salts in the soil (I suspect one or both of the later 2 possibilities) it's not so easy to remedy. Another possibility is a nutritional issue ......... and yet another is high soil temperatures caused by a direct sun load & little air movement indoors.
Here's the thing - it's much more difficult to diagnose the problem and try to correct it, working within the limitations of what might have caused it to begin with. Easiest is to repot (not just pot up) into a good soil and get your watering and nutritional supplementation on track. Your plant will respond favorably; and fortunately, it's the ideal time of the year to undertake the change. I would suggest that after you do the work, you put the plant outdoors in open shade to regain its vitality.
Al
