41. _______________ The most common cause of depression is genetics. Some people are born with low levels of serotonin and dopamine and as a result, it is hard for them to experience happiness from typical happy events. Another cause of depression is alcohol or drug abuse. Misuse of drug will alter the brain’s normal chemical balance and result in short-term or longterm depression. Finally, contextual factors such as failed relationships, traumatic events, or an abusive childhood can also trigger depression. There are many factors that can cause depression, and it is an illness that cannot be taken lightly.
(A) Depression is a serious illness that can be caused by many factors.
(B) Depression is a serious illness and we have to take it seriously.
(C) Some people have more chances to get depression than others.
(D) There is a strong relationship between depression and drinking and drug abuse.