Its causes are still unknown but may be partly genetic. Depression tends to run in families. Brain chemistry changes or hormonal imbalances can trigger onset of the illness. The death of a loved one. Although it's easily diagnosed by experts, depression can be tricky for its victims.
Some people know they have it.
Others suspect they have it. Still others don't have a clue. Remarkably, a person suffering from clinical depression can have suicidal thoughts every day without recognizing they are ill. You don't even think of yourself as anything worthy of pity, and then you go even deeper into the dark hole. That's when he started thinking about killing himself.