Depression

Depression is associated with normal emotions of sadness and loss, and can be seen as part of the natural adaptive response to life’s stressors. True ‘clinical depression’, however, is a disproportionate ongoing state of sadness or absence of pleasure that persists after the exogenous stressors have abated. Clinical depression is commonly characterised by either a low mood or a loss of pleasure in combination with changes in, for example, appetite, sleep and energy, and is often accompanied by feelings of guilt or worthlessness or suicidal thoughts. The Diagnostic and Statistical Manual of Mental Disorders (DSM-5) classifies ‘major depressive disorder’ (MDD) as a clinical depressive episode that lasts longer than two weeks and is uncomplicated by recent grief, substance abuse or a medical condition. MDD diagnostic guidelines according to the new DSM-5 allows for clinical depression to potentially be diagnosed during the initial stage of bereavement (assuming low mood and/or loss of pleasure is the predominant feature, not grief). Depression presents a significant socioeconomic burden, with the condition being projected by the year 2020 to effect the second greatest increase in morbidity after cardiovascular disease. The lifetime prevalence of depressive disorders varies depending on the country, age, sex and socioeconomic group, and approximates about one in six people. The 12-month prevalence of MDD is approximately 5–8%, with women approximately twice as likely as men to experience an episode.