Recognizing the Signs and Symptoms of Depression

Although everyone feels sad from time to time, major depressive disorder is a serious, persistent psychological condition that significantly impairs a person’s life in a broad variety of ways. Depression is common in the United States, affecting over 16 million adults every year. It’s the second most common family of psychological disorders, second only to anxiety disorders. But what is depression and how do you know if you or someone you love has it? 

Depression is a mood disorder that affects a person's thoughts, emotions, and behaviors. Symptoms may come and go, but to be diagnosed symptoms have to be severe enough to interrupt or interfere in a person's life and happen on more days than not, for at least two weeks. 

Common symptoms of depression include: 

• Feelings of deep sadness or hopelessness 
• Loss of interest in previously enjoyed activities 
• Inability to enjoy one’s self or find pleasure in anything (anhedonia) 
• Irritability, including flash outbursts of temper 
• Sleeping too much or having problems going to sleep or staying asleep 
• Eating disturbances—either eating much more than usual or losing one’s appetite 
• Anxiety 
• Restlessness, agitation, or a feeling of being on edge 
• Fatigue and persistent low energy 
• Slowed body movements (psychomotor retardation) 
• Feelings of hopelessness and helplessness 
• Feelings of guilt and worthlessness 
• Slowed thought processes, increased mental confusion 
• Poor concentration and impaired memory 
• Recurrent, intrusive thoughts of death or suicide 
• Unexplained physical problems like muscle aches, headaches, and stomach aches 

 Major depressive disorder is just one of a family of mood disorders. There are several subtypes, each of which has slightly different signs and symptoms, but in all cases, it’s a disturbance in a person’s ability to maintain a normal, balanced mood that’s the primary symptom. These are the most common types of depression: 

1. Major Depressive Disorder 
2. Persistent Depressive Disorder (dysthymia) 
3. Bipolar Disorder 
4. Seasonal Affective Disorder (SAD) 
5. Post-partum Depression 
6. Psychotic Depression  

Major Depressive Disorder 

Major Depressive Disorder (MDD) is what people refer to when they discuss “having major depression.” It involves intense feelings of deep sadness coupled with other disturbances in a person’s daily function, like poor sleep or too much sleep, as well as at least five of the other symptoms discussed above. MDD is the most common of depressive disorders 

Persistent Depressive Disorder (dysthymia) 

Persistent Depressive Disorder (PDD), or dysthymia, is similar to major depressive disorder in most ways. It’s less intense but still disruptive and is present on most days for at least two years or longer. It affects women more than men and occurs in 1.5 percent of US adults. Dysthymia can occur on top of a major depressive episode, leading to “double depression.”  

Bipolar Disorder 

Bipolar disorder, once called manic-depressive disorder, affects 3 percent of the US adult population. It affects men and women equally and in the overwhelming majority of cases, it is severe. Bipolar disorder has several subtypes including bipolar disorder type I, type II, and cyclothymia. 

Type I bipolar disorder has the same kind of depression seen in MDD, followed by a shift to a more normal mood, with a very energized, abnormally elevated mood occurring from time to time. A person's manic episodes may be rare, but it's their presence that determines the difference in a diagnosis of MDD or bipolar disorder. 

These manic episodes often result in the affected person engaging in behavior that’s very unlike them, including wildly overspending, sexual promiscuity, extreme risk-taking behavior, and grandiosity. In some cases, mania may lead to a complete break from reality, causing psychosis. 

In type II bipolar disorder, a person experiences a milder form of mania, called hypomania. Depression in type II bipolar disorder is as severe as that found in type I.  

Seasonal Affective Disorder (SAD) 

Seasonal Affective Disorder typically strikes during the winter in the northern hemisphere. It’s in part caused by the shift toward shorter days with fewer hours of sunlight, sunlight that’s less intense than at other times of the year. Researchers believe that the disruption to a person’s circadian rhythm caused by changing levels of sunlight is responsible for this kind of depression. SAD may also affect some people in the summer, although the most prominent emotion in summer SAD is high irritability. SAD is the only form of depression that reliably goes away on its own.  

Post-Partum Depression. Post-partum depression is more severe than the commonly experienced "baby blues." The signs and symptoms of postpartum depression are similar to those of major depressive disorder. There’s also overlap between post-partum depression’s symptoms and those of baby blues, but post-partum depression has symptoms that last longer and are more intense. Unlike baby blues, post-partum depression may strike months after a child is born. 

Psychotic Depression  

Psychotic depression, or depression with psychotic features, involves a person losing contact with reality. Delusions and hallucinations are common in psychotic depression. A person with delusions has beliefs that are illogical and contradicted by reality. Hallucinations involve hearing and seeing things that are not present. Command hallucinations, particular command auditory hallucinations occur when people hear voices telling them to kill themselves or others. Psychotic depression must be treated in a hospital. 

What Causes Depression? 

Depression is thought to be caused by disturbances in the way nerves in the brain produce and respond to chemical signals. These chemical signals include neurotransmitters and neuromodulators. For reasons not yet fully understood, nerve tissue in the brain may underproduce or overproduce these chemicals. Nerve tissue may also become less affected by normal levels of neurotransmitters.  

Treating Depression 

Although the biochemical imbalance that leads to depression in some cases can be corrected, treatment with medication alone isn’t enough to resolve the symptoms of depression. A major illness like depression touches all aspects of a person’s life. It can cause psychological and social problems that are beyond the scope of medication to address. 

For those reasons, treating depression is most effective when different modes of treatment are combined. Beyond medication, there are many kinds of psychotherapy (“talking therapy”) that are effective in helping people lead more satisfying lives. More recently, there are non-pharmacological treatments including repetitive transcranial magnetic stimulation (rTMS) and inducing a theta brain state with a Theta Chamber. These scientific advances have give people more options for treating their depression which allows for care tailored to each individual.