People thinking of suicide are not a bit blue (that passes) they are clinically depressed. There are normal things that people do when thinking about suicide, but thoughts of suicide is not healthy.
From the Medical Web
Warning signs that an individual is imminently planning to kill themselves may include the person making a will, getting his or her affairs in order, suddenly visiting friends or family members (one last time), buying instruments of suicide like a gun, hose, rope or medications, a sudden and significant decline or improvement in mood, or writing a suicide note. Contrary to popular belief, many people who complete suicide do not tell any mental-health professional they plan to kill themselves in the months before they do so. If they communicate their plan to anyone, it is more likely to be someone with whom they are personally close, like a friend or family member.
Individuals who take their lives tend to suffer from severe anxiety, symptoms of which may include moderate alcohol abuse, insomnia, severe agitation, loss of interest in activities they used to enjoy (anhedonia), hopelessness, and persistent thoughts about the possibility of something bad happening. Since suicidal behaviors are often quite impulsive, removing firearms, medications, knives, and other instruments people often use to kill themselves can allow the individual time to think more clearly and perhaps choose a more rational way of coping with their pain.
This is only information; if you care so much about what people think, it may be a need for attention more than a need to die.