The most basic symptoms of depressive episodes are called the three low symptoms, i.e. depressed mood, slowed thinking, and reduced volitional activity. Depressed mood means that patients tend to experience sad mood, not happy, often dominated by self-experience of pain, low, gray mood, accompanied by despair, hopelessness, helplessness, incompetence, and a sense of uselessness. Delayed thinking patients’ thinking behaves like rust and cannot express their thoughts effectively and accurately. Their delayed thinking can affect patients’ inattention and inadequate expression of content. Patients with decompensated mental activity show no expectation for the future, dominated by self-injury, suicide, self-guilt, self-blame, low self-evaluation, and low intention for the future.