According to Durkheim, suicide comes in four varieties—those who don't fit into a collective community, those who believe that death is necessary for some noble reason, those who slide too far into chaos, and those who slide too far into order. These four are explained for their sociological value, but the broader picture of Durkheim's analysis is obviously that he cares very deeply about people taking their own lives, so much so that he wants to spread awareness about what these phenomena are really like to those who suffer them, because after all, with enough heads up, many people could be treated for their issues.
In the last two types of suicide, the anomic suicide and the fatalistic suicide, the person is either sliding far too much toward chaos or order. The anomic suicide is driven by the waywardness one feels in chaos when they abandon the social norms of their community. Without the order that social assumption lends, a person can be brought to existential despair. But that also happens if one heads too far in the direction of order. Prisoners bemoan their imprisonment, and without the freedom to escape their controlled environment, they are often brought to despair. Then there are those that impose order on themselves, making slaves out of themselves.
The altruistic suicide is a feature of group think, from a sociological perspective, because it is what happens when a person (unlike the anomic suicide) fails to realize that the social norms that others believe around them may not be perfect and pure. In other words, a person can be talked into suicide by a collective, if they aren't thinking for themselves.
Finally, there is the egoistic suicide which comes from negative social experiences, which train a person to misunderstand their own situation. If they seemed happy, balanced, and optimistic, then society would welcome them, broadly speaking. Plus a person who feels rejected can rarely hide that—it's an intense emotion—and that makes people treat them in a way that makes them believe they are inferior, but it was never the case that they were inferior. In other words this kind of hopelessness comes from a person falsely believing that people would never accept them, either because their community is closed-minded, or because they haven't learned how to accept themselves and become socially successful.
Not exactly happy stuff, but at the end of the day, Durkheim is correct about one thing—suicidal depression cannot be stigmatized, or else those who are suicidal will feel scared or embarrassed to tell someone. Durkheim says that it is part of our social programming, our relationship to community, so we have to be willing to tell people when we feel desperate.
