Late-Life Depression

Abstract

Over the past half-century, life expectancy has been increased (1). Therefore, the world's elderly population is growing at an unprecedented rate and currently is at its highest level in human history (2). According to WHO estimation, mental health disorders are the most common cause of disabilities in people worldwide and over 300 million people are estimated to suffer from depression, equivalent to 4.4% of the world's population. Between 1990 and 2007, the number of all-ages YLDs attributed to depressive disorders increased by 33·4%, becoming the third leading cause of all-ages YLDs in 2007 (3). The point prevalence of the major depressive disorder in the elderly is more than 5% in men and about 8% in women. Although depression affects people of all ages, the risk is increased by poverty, unemployment, life events such as the death of a loved one or other kinds of loss, physical illness, and alcohol and substance use (4). Depressive symptoms of the elderly are even more prevalent in Iran. In a meta-analysis, prevalence of depression among Iranian elderly was estimated to be 43% of whom 5% suffered from severe symptoms of depression (5). Diagnosis of depression and depressive symptoms like dysthymia is almost clinical and possible through an interview. According to the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), the diagnosis of a Major Depression Episode (MDE) requires five or more symptoms to be present within 2 weeks (6). One of the symptoms should be a depressed mood or anhedonia. The secondary symptoms are appetite or weight changes, insomnia or hypersomnia, psychomotor agitation or retardation, fatigue or loss of energy, diminished ability to think or concentrate, feelings of worthlessness or excessive guilt, and suicidality (6). Unfortunately, DSM and other systems of classification of the disease do not have age-specific diagnostic criteria for MDE in the elderly and many symptoms of depression like loss of interest, lack of energy, physical complaints can be caused by medical diseases. However, ageism among patients and health care providers is an important concern which indicates depressive symptoms are part of the normal aging process.