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He may be experiencing the 'conservation withdrawal' that occurs when a person starts to hit a low spot or depression. They pull back from outside contact because it takes too much energy. He may also feel the need to get off the computer & computer games because he's gotten too far into them in a manic phase. It's hard to tell from here, but he may also want to end your interactions for some other reason.
People with bipolar come and go when they're not medicated properly, but if he is, he may just want to move on and start fresh. If it's untreated bipolar, he'll most likely swing back and try to reconnect. If this is a romantic situation, I wouldn't be waiting for him to return. He'll contact you if he wants to, and if he doesn't, you should assume first that it's a conscious decision. Always remember that bipolar patients are people with personalities preferences first, and that most decisions come from that place. How and when they get delivered can be skewed, but there is often a grain of truth in their communications or cut offs.
My best to you.
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