( CNN ) -- Robert Enke , the goalkeeper for the German national football team who killed himself on Tuesday , was suffering from depression , his widow has revealed . Valentin Markser , a doctor who treated Enke , said the goalkeeper first sought treatment in 2003 , when he lost his starting place at Barcelona and developed anxieties and fear of failure . The couple 's biological daughter died three years ago from a heart problem when she was aged just two . Dr. Charles L. Raison , Clinical Director of the Mind-Body Program at Emory University School of Medicine , in Atlanta , answers some key questions about some of the issues associated with depression . What are the signs or symptoms that someone is suffering from this illness ? The classic symptom of depression is feeling emotionally down or blue , but when humans start feeling this way a whole bunch of other symptoms usually tag along . When people feel emotionally depressed they tend to lose interest in the world around them and their ability to experience pleasure withers . They often become very hopeless and feel overwhelmed by responsibilities that would normally be no problem for them . They have trouble thinking and concentrating , and when depression is severe they can feel like they are losing their minds . Depressed people often feel very badly about themselves . They can be haunted by guilt and consumed by negative thoughts that run over and over again like a bad movie . This level of psychic misery begins to make death seem like a form of relief , so it is not surprising that most depressed people spend at least some of their time thinking about suicide . Depressed people almost always have changes in their sleep and appetite . In addition , people with depression typically experience tremendous fatigue and are often plagued by aches and pains in their bodies for which no bodily cause can be found . What causes depression ? Depression is caused by an interaction between genes and environment . Some people carry genes that make them so prone to depression that almost any degree of hardship will bump them into depression . At the other extreme there are environments that are so terrible that all but the most resistant people will develop depression . Psychological stress and medical illness are the two royal roads to depression . Almost all episodes of depression are set off by one or the other of these factors , although the more often a person is depressed the less adversity is needed to set off a new episode . That is one type of answer to the question of what causes depression . Scientists are discovering a different kind of answer which has to do with the types of abnormalities in the brain and body that are characteristic of people with depression . We might say that depression is caused by hyperactivity of body-brain danger pathways and not enough activity in brain areas that help us get a grip on our emotions . In this way depression is very much a physical illness . What can be done to treat it ? The short answer is `` many things '' . In general , treatments boil down to either pharmacological or behavioral . In the pharmacological category are numerous antidepressants and other psychotropic drugs , such as lithium and atypical antipsychotics . In the behavioral realm are a number of psychotherapeutic techniques , ranging from psychoanalysis to behavioral therapy . Overall , medications and therapy appear about equal in efficacy . Recent data suggest that therapy might have a longer-lasting protective effect than medications once treatment has stopped . In addition to medications and therapy , recent studies suggest that vigorous exercise is also an effective treatment for depression . Have attitudes within the medical profession changed ? No one in medicine -- in my experience -- questions either the reality or validity of major depression . In fact , far from disputing the importance of depression , what I usually find is a huge hunger on the part of the medical profession to learn more so they can better help their patients . The World Health Organization now places depression as the fourth most disabling medical condition worldwide and estimates it will rise to number two by 2020 . The days when doctors looked askance at depression as a clinical entity are long gone .
Dr. Charles Raison tells CNN about the symptoms and causes of depression . Some people carry genes that make them more prone to depression . When people feel emotionally depressed they tend to lose interest in the world around them .