One of my past colleague smoked pot everyday and one night was franticly searching for his "dose" and he was getting extremely frustrated because he couldn't fi

One of my past colleague smoked pot everyday and one night was franticly searching for his "dose" and he was getting extremely frustrated because he couldn't find it. He told me that it got to a point where he got mad and literally blacked out! He found himself in a black void which he described as very disturbing and hellish because all he could feel was dread and the sound of screams. He never touched any substances after that and was shook up when he told me that story.