Push pen anxiety is a psychological state characterized by one's excessive push-in push-out of his or her retractable pen, often due to stress or boredom. It is addicting because of its sound and its motion of going up and down. You kind of get hypnotized. 

“按笔焦虑症”描述的是一种心理状态，就是在无聊或者压力大的情况下不停地按动伸缩笔的笔帽按钮。这种按动发出的声音和上下伸缩的动作会有点让人上瘾，可能会让你沉迷其中。

For example:

That kid at the back of the class has a serious case of push pen anxiety. He has been pushing his pen button for nearly half an hour.

班里坐最后一排的那个孩子有严重的按笔焦虑症，他已经连续按动那个笔帽按钮半个小时了。