Depressive Disorders (Depression)
Depressive disorders are a family of mood disorders and they include Major depressive disorder, dysthymic disorders, and Depressive disorder not otherwise specified (NOS); all are often collectively referred to as simply "depression."
Depression is one of the mostly commonly occurring types of mental illness and identifying the signs and symptoms can help with early intervention.
One of the most telling signs of depression is sudden or unexplained social isolation. Individuals who are suffering from depression tend to lose interest in engaging socially with others. They may stop going out with friends, fail to return phone calls, or frequently call in sick to work or school. They tend not to find social interactions as enjoyable or rewarding as they used to, and may even dread having to deal with other people.
Changes in Sleep
Individuals suffering from depression tend to experience changes in sleeping patterns, although how these patterns change can vary greatly from person to person. Some people have a much more difficult time falling asleep than they used to and may find themselves lying awake in bed for several hours.
Others fall asleep just fine, but frequently wake up throughout the night when previously they would have slept through. Still others may find that they suddenly need an extra three or four hours of sleep, or that they never feel fully rested. Any significant changes in sleep can be warning signs of depression.
Changes in Appetite
Depression tends to affect people's appetites in a number of different ways. Some experience a drastic reduction of appetite and may even skip meals without realizing it. Others may have an increased desire for food which ultimately results in weight gain. Still others may simply lose their taste for certain foods that they once enjoyed.
Reduced Energy Levels
Individuals suffering from depression also tend to experience significantly reduced energy levels and a general sense of fatigue. Although these feelings are often related to problems with sleep or appetite, they can also occur independently of either of these signs of depression. This reduction in energy can lead to lower hygiene levels and lack of personal care, decreased productivity at work or school, and general neglect of daily tasks or responsibilities.
Anhedonia (Lack of Interest in Activities or Hobbies)
Anhedonia, literally "the lack of joy," refers to a loss of interest in hobbies or activities which previously were enjoyed and felt like fun. People suffering from depression often stop engaging in hobbies or other enjoyable activities to an extent that is noticeable by other people. Hobbies or activities that are physical in nature such as exercise or sex seem to be particularly affected by depression.
Web MD: Risk Factors and Warning Signs for Depression and Suicide – https://www.webmd.com/depression/guide/depression-recognizing-signs-of-suicide
Web MD: Untreated Depression – https://www.webmd.com/depression/guide/untreated-depression-effects
Psychotherapy: 15 Warning Signs of Depression – https://www.psychotherapist.net/depression.html