They have been influenced. By themselves learning they have more to live for or by somebody close to them such as family or an relationship
Triceps would benifit most from these excerises.
There is many reasons why people have depression. Loss of a family member, bullying, physically abused or mentally abused. Persistent Depressive Disorder is Depression that lasts about 2 years or more it could cause change in appetite, sleep to much or too little, also a lack of energy or fatigue. You could also have low self-esteem even have trouble concentrating and making decisions. You could also feel hopeless you would need therapy and sometimes medications. There is about 9 different depression or more I hope this helps.