What is Depression?

Feelings of sadness are a normal reaction to life’s problems or disappointments, but if sadness lasts longer than two weeks and affects your work, studies, or day-to-day activities, it may represent a medical condition called depression.

Depression is a serious mood disorder. It can take different forms, but is typically characterized by feelings of sadness, helplessness, hopelessness, and worthlessness. People with depression may describe feeling empty, angry, aggressive, or restless. Depression can begin at any age, although is most commonly diagnosed during the early adult years. Symptoms may start gradually over several weeks or months but can also appear suddenly.

People with depression may not recognize the seriousness of their feelings and may be reluctant to seek help. They also may not realize that depression can cause physical symptoms such as aches and pains, sleep problems and a change in appetite. Fortunately, effective treatments are available for depression, such as medications and psychotherapy. These can be used either alone or in combination, depending on the type of depressive illness, its severity, and the individual’s response.

Causes of Depression

In the United States, depression affects approximately 15 million people each year. It tends to run in families and individuals with first-degree relatives with depression are three to four times more likely to also be affected by it. It may be inherited genetically, although certain behaviors that can be learned or picked up at home may also contribute to its onset. However, depression also occurs in some people with no family history of depression which indicates that there is not one single cause and it likely involve a complex interplay among several biological and environmental factors.

Brain chemistry also plays a significant role in the development of depression. Scientists have seen important differences in the brain scans of people suffering from depression and those of healthy individuals. Based on these findings, the areas of the brain responsible for mood regulation, sleep, appetite, and thinking did not seem to function normally in persons with depression. Neurotransmitters or brain chemicals produced in the brain are thought to play a role in depression. Studies have shown that changes in the levels and activities of neurotransmitters such as serotonin, norepinephrine, and dopamine contribute to the alteration of mood and behavior.

Studies have identified four factors that seem to have a causal relationship with depression include gender, stressful life events, negative childhood experiences, and certain personality traits. Stressful life events such as marital difficulties, health problems, the loss of loved ones, and job loss are associated with an increase in the tendency to become severely depressed. Persistent negative thoughts contribute to and worsen a depressed mood. Poor relationships with siblings, family members, and friends are also common in children and teens with depression. Also, children who show depressive symptoms also usually have a parent who also exhibits the same problems or symptoms.

Although depression affects both men and women, women are more likely to be diagnosed with this condition. In fact, about one in eight women develop depression during their lifetime. Several factors may contribute to women’s increased risk for depression including hormonal, reproductive, developmental, and other biological differences. It is believed that the effects of female hormones influence the brain chemistry that controls emotions and moods especially during specific times during a woman’s life, particularly at puberty, during and after pregnancy and childbirth, and at menopause.

Among women who experience premenstrual syndrome, approximately 3 to 5 percent experience depression that is severe enough to be classified as Premenstrual Dysphoric Disorder (PMDD). Women with PMDD typically have depression, mood swings, anxiety, and irritability a week before the menstrual period, which resolve once menstruation has ended.

Postpartum Depression occurs within the first year following childbirth and an estimated 10 percent of all new mothers are diagnosed with this. The physical changes and the new responsibilities in becoming a mother and caring for a newborn can be overwhelming, making new mothers vulnerable to depression.

A number of psychological and social factors can also lead to an increased risk of depression among women, including family and social responsibilities, stress from increased expectations of women, and increased rates of physical and sexual abuse.

Certain medications used for the treatment of medical conditions like hypertension, hypothyroidism, seizures, cancer, pain, contraception, and other psychiatric conditions may cause depression as a side effect (eg, hormones, steroids, interferon). Use of illegal substances like cocaine, narcotics, amphetamine, and alcohol also has been associated with depressive illnesses.

Depression may also occur along with other psychiatric disorders such as schizophrenia, anxiety, and attention-deficit hyperactivity disorder (ADHD).