I find that getting outside, even for a wheelchair roll around a parking lot if I can't make it to the park for a short stroll with my canes or walker, really helps my mood. I have been known to stagger out to my balcony, lean on my railing and fill my lungs with fresh air (OK city air, but it's fresher than the air in the condo). There's something about breathing deeply outside that raises my endorphin levels.