Timothy is 16 years old and in the tenth grade. For the past six months, Timothy seems to be lethargic. He comes into the classroom and spends the time either sleeping or displaying tiredness. He is an avid skateboarder competitor. For the past months, Timothy displayed a lack of interest in any aspects of the sport. During this same period, Timothy lost about 15 pounds as he no longer has an appetite for food. Timothy's science teacher reported that Timothy seemed to have a preoccupation with death as displayed in a science report that Timothy submitted. What characteristic of emotional disturbance does Timothy appear to exhibit?