It\u2019s completely natural to feel sad when a loved one, friend or beloved pet dies, or even when you read news about strangers losing their lives to natural disasters or acts of terrorism. Too often, sadness and depression are lumped together, which can have negative consequences. Depression is typically associated with the primary symptom of pervasive sadness, making it difficult for many people to differentiate between these two common psychological states. This confusion can lead to people overreacting when someone they know is sad, or conversely, mistaking far more serious depression for sadness and not seeking treatment. Sadness This is a normal human emotion most people experience countless times in a lifetime. It can be triggered by a difficult, hurtful, challenging or disappointing event, news, experience or situation. Withdrawing from others temporarily, becoming quiet or crying are indications a person is feeling sad. The feeling of sadness passes when the emotional hurt subsides. Mild Depression This is a common mental state, impacting an estimated 15% of U.S. adults. Minor depression is different from normal sadness, which impacts 29.8% of the population. It is a serious medical condition resulting in reduced quality of life and associated professional and personal disabilities. About 16% of people with mild depression experience unemployment. Clinical symptoms include: \tDepressed mood including sadness, sorrow, irritability, despondency or melancholy \tMood swings during the day with diminished emotional response (flat affect) \tMore prominent mood changes in reaction to current life events Depression Unlike sadness, depression (major depressive disorder) is a serious mental illness, not an emotion. Depression is the leading cause of disability worldwide, impacting more than 300 million people and a major contributor to the overall global burden of disease. Major depression can cause unrelenting sadness and is associated with high rates of suicide. As many as 60% of suicides are attributed to major depression. Diagnostic Criteria for Major Depressive Disorder Research and clinical evidence indicate the death of a loved one can precipitate major depression, as can other stressors, such as losing a job or being a victim of a physical assault or major disaster. It is generally considered acceptable for people who have experienced a defined loss (e.g. bereavement or relationship breakdown) to become withdrawn, silent and tearful. In the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV), clinicians were advised to refrain from diagnosing major depression in individuals within the first two months following the death of a loved one, referred to as the \u201cbereavement exclusion.\u201d This exclusion has been dropped in DSM-V, although it can be difficult to differentiate normal bereavement from depression. Bereavement-related depression tends to impact people with other vulnerabilities to depressive disorders, and recovery may be facilitated by antidepressant treatment. At least five of the following symptoms must be present during the same two-week period, occur nearly every day and represent a change from previous functioning. These symptoms are similar to the aforementioned signs. \tDepressed state most of the day, identified by oneself or others \tPersistent and significantly decreased interest in all or most activities previously enjoyed \tNotable weight change (loss or gain) or decreased\/increased appetite \tInsomnia or hypersomnia (excessive sleepiness) \tPsychomotor changes (e.g. constant restlessness or slowed movements) \tFatigue, tiredness or loss of energy \tFeelings of worthlessness or excessive guilt \tDiminished ability to think, concentrate or make decisions \tRecurrent thoughts of death, suicidal ideation, a suicide attempt or specific plan for committing suicide Additional Diagnostic Criteria \tThe aforementioned symptoms cause clinically significant distress or impair everyday function \tThe depressive episode cannot be attributed to the physiological effects of a substance or other medical condition \tThe occurrence of the episode is not better explained by a specified or unspecified schizophrenia spectrum disorder or other psychotic disorders \tThe individual has never experienced a manic or hypomanic episode Research on Depression vs. Sadness A 2013 Spanish study on 344 participants found nearly 70% conceptualized sadness without a perceived cause as a mental illness (primarily depression). Demographics associated with perceiving sadness with or without cause as illness included being age 65 and older, a low level of education and being unemployed. Seeking help from a psychiatrist or psychologist was a more likely scenario for sadness without cause than with cause (54.4% vs 37.55%) and predicted seeking medical attention in general. Individuals who perceived sadness as misfortune were more likely to recommend the sad person get better on their own. Severe emotional distress precipitated by a loved one\u2019s suffering was seen more frequently as a normal response, while intense sadness in the absence of any cause was seen as pathological. Researchers suggested mental health professionals carefully explore an individual\u2019s understanding of their own symptoms and their wider social and cultural context to gain insights into the subjective experience of illness. Clinical depression and anxiety disorders frequently occur in people struggling with substance abuse and other destructive behaviors. Unlike sadness, therapeutic treatment is essential for individuals suffering from depression or co-occurring disorders. If you or someone you know is suffering from symptoms of depression, seek professional help as soon as possible.