Bipolar disorder or "manic depression" is a different condition to acute depression and is not treated with anti-depressants such as amitriptyline.
Harrow found a working cell phone that had been hidden for at least a year. No way a cell phone battery would not be dead after a year. However, you can clearly see that he is looking at the phone while it's plugged in. Therefore, the phone may have been dead but he was able to charge it.