According to a 2004 report by the World Health Organization, major depressive disorder is the leading cause of disability in the United States among those aged 15 to 44. This statistic underscores the impact of the following mental and emotional symptoms of depression. Because these symptoms may also be signs of comorbid psychological disorders or medical problems, it is important to consult a qualified healthcare professional for proper diagnosis and treatment.
Mood
Depression causes feelings of persistent sadness and emptiness. Individuals may feel varying degrees of worthlessness, guilt over things they have or have not done in the past, and self-dislike. They often feel hopeless about the future and helpless to bring about change in their lives.
Irritability
Depression can cause irritability, agitation and anxiety. Those who are depressed may feel unusually angry and frequently lose their temper over situations that usually would not provoke such strong emotions.
Loss of Interest
Depression leads to a loss of interest in daily activities, relationships, work, entertainment, and hobbies. Individuals who feel depressed either muddle through these activities without enjoyment, or stop participating in them altogether because they have lost the motivation to do so.
Sleep Disturbances
Other symptoms of depression often produce significant impairment in sleep patterns, resulting in hypersomnia (sleeping an excessive number of hours each day) or insomnia (difficulty sleeping at all). Sleep disturbances may also manifest as trouble falling asleep or trouble staying asleep characterized by frequent waking during the night.
Impairment in Mental Functioning
Depressed individuals may note a decline in cognitive or mental functions. It's common to experience an inability to make decisions and have trouble concentrating. A slowed thinking process or forgetfulness are also common. People with depression may complain of memory loss, have trouble remembering events and details, and become more disorganized than usual. Usually these cognitive functions return to normal after the depressive episode has resolved.
Social Impairment
Individuals suffering from depression often isolate themselves from family and friends and stop participating in social activities. They may not want to burden loved ones with their problems, or may feel uncomfortable revealing the seriousness of their emotional suffering. Unfortunately, self-imposed isolation usually worsens feelings of hopelessness, helplessness and sadness. In severe cases, depressed individuals can come to feel so safe in their isolation that they start to fear social situations, developing anxiety about going out in public.
Suicidal Thoughts or Behavior
There is a known link between suicide and lifetime depression. Those suffering from depression are likely to experience recurrent thoughts about death, thoughts about committing suicide that include the development of a plan, or suicidal gestures or attempts.
