Depression - in this non-medical sense - may be caused by a loss or personal failure (as in sadness), personal rejection, or indeed by any undesired outcome or situation, particularly if the situation happens or continues despite the efforts of the subject.Depression, or, more properly, a depressed mood, may in everyday English refer to a state of melancholia, unhappiness or sadness, or to a relatively minor downturn in mood that may last only a few hours or days. A mental disorder marked by altered mood, this may occur daily with the addition of diminished interest or pleasure in most or all activities. Symptoms can be as follows: poor appetite or weight loss, or weight gain, insomnia or hypersomnia, feelings of hopelessness, worthlessness or inappropriate guilt, difficulties with concentration and thinking, and recurrent thoughts of death or suicidal ideations.