Major depressive disorder is a syndrome that negatively affects a person’s life. It comprises certain symptom sets that disables the sufferer’s ability to function in daily life. People with depression live in a state of low mood and aversion to activity. In fact, they often feel worthless and unable to function properly.
Interestingly, the word depression comes from the late Latin word “depressare” and the classical Latin word “deprimere,” which literally means to press down. Researchers suggest that the term indicates a feeling of heaviness, of being “pressed down,” or feeling sad, blue or simply down.
Depression includes different phases and people may experience one or several of them in a certain period of time. Some people have signs of depression that last longer, with a mix of severe and less severe phases. Others will develop chronic depression that lasts for years. Some four common phases of depression include:
Depressive episode — a state of low mood and aversion to activity that goes away after a certain amount of time.
Relapse — when signs of depression return within six months after the last depressive episode.
Recurrent depression — when signs of depression return more than six months after the last episode, or even years later.
Chronic depression — when depressive episodes last longer than two years.
It’s perfectly normal to feel sad and lonely at times — this is a common reaction to life’s struggles. However, when feelings of sadness, loneliness and depression become so overwhelming that they keep you from social interactions, physical activity and other normal life events, you may need to seek the help of a counselor or health care provider. Although there are complex and varied features of depression, there are some common signs of depression that can help you to make an accurate diagnosis.
People who are depressed often feel exhausted and unable to carry out physical or mental work. In a large study including almost 2,000 depressed patients across six countries, 73 percent of patients agreed that they experienced tiredness.
Insomnia is a frequent symptom of depression. Other signs of depression are disturbances in the ratio of rapid eye movement (REM) sleep to non-REM sleep, decreased slow-wave sleep and impaired sleep continuity. According to research published in Dialogues in Clinical Neuroscience, about three quarters of depressed patients have insomnia symptoms, and hypersomnia (or excessive sleepiness) is present in about 40 percent of young depressed adults and 10 percent of older patients. The symptoms cause huge distress, have a major impact on quality of life and are a strong risk factor for suicide.
Cognitive Dysfunction or Difficulty Concentrating
Signs of cognitive dysfunction in depressed patients include disturbances in psychomotor speed, memory, verbal fluency, attention, executive functions (such as planning and problem solving) and processing speed. According to research published in Annual Review of Clinical Psychology, people who show signs of depression also have difficulty disengaging from negative material. They also have deficits in cognitive control when processing negative material.
Feelings of Worthlessness or Hopelessness
According to research published in the Journal of Affective Disorders, cognitive models predict that vulnerability to depression is due to a bias to blame oneself for failure in a global way. This results in excessive self-blaming emotions, decreased self-worth, hopelessness and depressed mood. A study involving 132 patients with major depressive disorder found that feelings of inadequacy, depressed mood and hopelessness emerged as the most closely co-occurring and consistent symptoms, affecting more than 90 percent of patients.
Irritability or Restlessness
Clinical studies of depressed children and adolescents have shown that the most frequently reported symptom in moderate depression is irritability. Research shows that irritability is more likely in female, young, unemployed people who are lower in functional status and quality of life, and have a history of at least one suicide attempt. Irritability with anger attacks might be present in more than one-third of patients with major depressive disorder, according to research published in Molecular Psychiatry.
Loss of Interest in Hobbies or Activities
One of the main signs of depression is reduced work and interest. It’s an essential requirement for the diagnosis of major depressive episode. The scientific term for a reduced ability to experience pleasure is anhedonia. Depressed people no longer value activities and hobbies that once brought them pleasure. People may begin to feel as though they have no purpose. They lose social connections because of their inactivity in the community, at work or within the family.
According to research published in the Indian Journal of Psychiatry, many of the easily noticeable food patterns that precede depression are the same as those that occur during depression. These may include poor appetite, skipping meals and a dominant desire for sweet foods. There is a growing body of evidence proving that nutritional factors are intertwined with human cognition, behavior and emotions.
Researchers published a study in the American Journal of Psychiatry in which they found that many of the brain regions responsible for appetite and responses to food are implicated in depression. Researchers found that people with depression-related increases in appetite exhibited greater hemodynamic (blood flow) activity to food stimuli, while depressed patients who experience appetite loss exhibited hypoactivation of insular regions of the brain.
Persistent Aches or Pains
Physical signs of depression include chronic joint pain, limb pain and back pain. According to research conducted at the University of Texas Southwest Medical School, physical pain and depression have a deeper biological connection than simple cause and effect. The neurotransmitters that influence both pain and mood are serotonin and norepinephrine; dysregulation of these transmitters links to both depression and pain. Researchers suggest that in general, the worse the painful physical symptoms, the more severe the depression. Elevated rates of suicidal thoughts are also found in patients with chronic pain.
Data indicates that emotional stress and depression might influence the development of gastrointestinal disorders. In a 2015 study, stress and depression were related to functional dyspepsia (or discomfort in the chest and abdomen), irritable bowel syndrome and reflux esophagitis. Depression was also linked to stomach ulcers, and benign tumors and cancer of the colon and stomach.
Studies show that 90 percent of depressed patients have co-occurring anxiety symptoms and approximately 50 percent of depressed patients meet the criteria for a comorbid anxiety disorder, meaning they simultaneously experience signs of depression and anxiety, two conditions, at the same time.
An important and often overlooked sign of depression is sexual dysfunction. Research shows that low libido may contribute to deteriorating interpersonal/marital relationships and further exacerbate depression. Although patients most often report decreased libido, difficulties with arousal, resulting in vaginal dryness in women and erectile dysfunction in men, and absent or delayed orgasm are also prevalent. According to a 2009 review conducted at the University of Toronto, sexual dysfunction is also a frequent adverse effect of treatment with most antidepressants and is one of the predominant reasons for premature drug discontinuation.
Thoughts of Suicide
Data published in Annals of General Psychiatry suggests that between 59 and 87 percent of suicide victims suffer from major depression. Suicide has proven to be a multicausal behavior. People who experience anxiety and depression simultaneously are at a greater risk of developing suicidal thoughts. Research also shows that being male, experiencing adverse life situations, social losses such as the death of a loved one, loss of work or income and cognitive decline, physical disease and acute psycho-social stressors are also risk factors.