What is Depression?
Most people assume depression has to do with being sad. Depression is caused by a depletion of chemical messengers in the brain that are essential for normal functioning.
With depression, the brain is in a state of chemical imbalance. In healthcare, depression is short for a serious medical condition which involves multiple areas of brain functions and many disabling symptoms. Sadness is only one possible symptom.
What is Major Depression?
Major depression is a serious medical illness, affecting 15 million American adults (approximately 5-8 percent of the adult population) in a given year. Unlike normal emotional experiences of sadness, loss or passing mood states, major depression is persistent and can significantly interfere with an individual’s thoughts, behavior, mood, activity and physical health. Among all medical illnesses, major depression is the leading cause of disability in the United States and many other developed countries.
Depression occurs twice as frequently in women as in men for reasons that are not fully understood. More than one-half of those who experience a single episode of depression will continue to have episodes that occur as frequently as once or even twice a year. Without treatment, the frequency of depressive illness and the severity of symptoms tends to increase over time. Left untreated, depression can lead to suicide.
Major depression, also known as clinical depression or unipolar depression, is only one type of depressive disorder. Other depressive disorders include dysthymia (chronic, less severe depression) and bipolar depression (the depressed phase of bipolar disorder).
People who have bipolar disorder experience both depression and mania. Mania involves unusually and persistently elevated mood or irritability, elevated self-esteem and excessive energy, thoughts and talking.
Mood disorders are treatable, physical illnesses of the brain involving changes in energy, behavior, thought and mood. A person may experience periods of depression or alternating periods of depression and mania (known as bipolar disorder or manic depression).
Symptoms of Depression
- Sad, empty, irritable or tearful mood most of the day, nearly every day
- No interest in or pleasure from activities once enjoyed
- Major changes in appetite or body weight
- Insomnia or sleeping too much
- Feelings of restlessness or being slowed down
- Fatigue, exhaustion, lack of energy
- Feelings of worthlessness or excessive guilt
- Inability to concentrate or make decisions
- Thoughts of death or suicide
- If someone has thoughts of death or suicide, get help immediately by calling a medical professional or 1-800-273-TALK.
Symptoms of Mania
- Feeling overly energetic, high, better than good or unusually irritable for at least one week
- Very high self-esteem, feeling all-powerful
- Decreased need for sleep without feeling tired
- Talking more or faster than usual, pressure to keep talking
- Racing thoughts, many ideas coming at once
- Distracted easily, thoughts or statements jumping from topic to topic
- Increase in goal-directed activity, restlessness
- Excessive pursuit of pleasure (e.g., financial or sexual) without thought of consequences
Who Gets Depression?
Depression can occur at any age. One out of four women and one of eight men will suffer a depressive episode at some time during their lifetime. Depressive episodes frequently occur at difficult transition points, such as a death, divorce, job change, or change in living circumstances or expectations. People with chronic medical conditions are much more vulnerable to depression. Failure to recognize this disorder and get proper treatment is a major health hazard, resulting in poor performance at home, school, and work. The worst outcome is suicide.
What are the Symptoms of Major Depression?
The onset of the first episode of major depression may not be obvious if it is gradual or mild. The symptoms of major depression characteristically represent a significant change from how a person functioned before the illness. The symptoms of depression include:
- Persistently sad or irritable mood
- Pronounced changes in sleep, appetite and energy
- Difficulty thinking, concentrating and remembering
- Physical slowing or agitation
- Lack of interest in or pleasure from activities that were once enjoyed
- Feelings of guilt, worthlessness, hopelessness and emptiness
- Recurrent thoughts of death or suicide
- Persistent physical symptoms that do not respond to treatment, such as headaches, digestive disorders and chronic pain
When several of these symptoms of depressive illness occur at the same time, last longer than two weeks and interfere with ordinary functioning, professional treatment is needed.
What are Some Signs of Depression?
- Loss of interest or pleasure in nearly all activities (e.g. isolation, lack of participation in activities.
- Feelings of hopelessness (e.g. “I’m never going to feel better”)
- Significant change (increase or decrease) in appetite and/or sleeping habits, documented consistently over two weeks
- Psychomotor agitation (e.g. pacing, inability to sit still, pulling skin)
- Psychomotor retardation (e.g. slowed speech and body movements, muteness, slow thinking)
- Decreased energy or fatigue (e.g. “I’m always tired”)
- Feelings of worthlessness or guilt (e.g. “Everything is my fault”)
- Inability to concentrate (e.g. forgetting recent reading material)
- Suicidal ideation or attempt
- Disturbed sleep
- Chronic impatience
- Feeling numb
- Frequent tears
- Sad, anxious or empty mood
- Sleeping too much or too little, middle of the night or early morning awakening.
- Reduced appetite and weight loss or increased appetite and weight gain
- Loss of pleasure in interest or activities once enjoyed (including sex)
- Irritability restlessness, persistent physical symptoms that so not respond to treatment
- Chronic pain or digestive disorders.
- Difficulty concentrating, remembering or making decisions
- Fatigue or loss of energy
- Feeling guilty, hopeless or worthless
- Thoughts of death or suicide
How is Depression Diagnosed?
Currently there are not any special blood tests or scans available to indicate there is a chemical imbalance; although, there is intensive ongoing research attempting to find an easy way to objectively measure the presence of a chemical imbalance. Currently a diagnosis is made by assessing which symptoms you are experiencing, their severity, and the length of time they have been present. Nine areas of brain function are assessed. To fit the criteria for depression, at least four of these nine areas must be affected for at least two weeks.
The nine areas of brain functioning that are assessed are:
|Area of Brain Function||Explanation|
|Sleep||Disturbance in normal pattern, sleeping too much or trouble falling asleep and/or staying asleep|
|Mood||Ongoing feelings of sadness, anxiety, irritability or numbness, or any combination of these|
|Appetite||Disturbance in normal pattern, eating less or more|
|Speed||Body and/or thoughts feeling slowed down (sluggish) or sped up (racing)|
|Self-Worth||Feeling worthless, helpless, or guilty|
|Outlook on life||Hopelessness and/or frequent thoughts of death or suicide|
|Concentration and memory||Inability to think clearly, focus and remember, make decisions, or any combination of these|
|Energy||Tiredness and/or restlessness|
|Motivation and Interest||Loss of interest in people, things, or activities that once brought pleasure, including sex|
Some Additional Symptoms of Depression
- Difficulty in beginning projects
- Inability to concentrate
- Difficulty completing projects
- Chronic aches and pains
- Loss of interest or pleasure in ordinary activities
- Agitation or restlessness
Causes of Depression
- Imbalance in brain neurotransmitters
- Co-occurring depression: cancer, heart disease Alzheimer’s, diabetes, or hormone disorders can trigger depression
- Negative thinking: pessimism, low self-esteem, worry excessively
- Family history: genetic component increases likelihood, but not always
- Difficult life events: situational depression, death, moving, divorce, and other stresses
- Certain medications can cause depression
- Alcohol or drug consumption creates depression and is also a sign of depression
The most common cause of depression is stress. Stress can be defined as feeling emotionally overloaded over a prolonged period. This overload literally causes the nervous system to work overtime without a break to renew itself. This eventually depletes the chemical messengers (neurotransmitters) that are critical for cells to communicate with each other. You experience different symptoms of depression depending upon in which area of the brain the chemical depletion occurs. The severity of symptoms is likely linked to the severity of depletion in any given area of brain function.
In helping to determine the causes of depression, your healthcare provider asks about your family. How your brain is put together (genetics) determines in which brain areas trouble may occur if you are overloaded or stressed. Often the same vulnerabilities are manifest in family members because of genetic similarities. Family members often respond to the same medications.
Sometimes stress is not the cause of depression, but the brain is simply vulnerable to sub-optimal functioning in certain areas. This brain dysfunction may be chronic, or may have a rhythm of its own tied to a variety of factors (hormonal shifts, change of seasons, medical conditions, etc.). Again, your healthcare provider tries to sort out possible causes and assist you to correct what can be corrected to help your system heal. Another common cause of chemical imbalance is illness in other parts of the body. Chronic and serious medical conditions commonly make the brain more vulnerable to imbalance.
There is no single cause of major depression. Psychological, biological and environmental factors may all contribute to its development. Whatever the specific causes of depression, scientific research has firmly established that major depression is a biological, medical illness.
Norepinephrine, serotonin and dopamine are three neurotransmitters (chemical messengers that transmit electrical signals between brain cells) thought to be involved with major depression. Scientists believe that if there is a chemical imbalance in these neurotransmitters, then clinical states of depression result. Antidepressant medications work by increasing the availability of neurotransmitters or by changing the sensitivity of the receptors for these chemical messengers.
Scientists have also found evidence of a genetic predisposition to major depression. There is an increased risk for developing depression when there is a family history of the illness. Not everyone with a genetic predisposition develops depression, but some people probably have a biological make-up that leaves them particularly vulnerable to developing depression. Life events, such as the death of a loved one, a major loss or change, chronic stress and alcohol and drug abuse, may trigger episodes of depression.
Some illnesses such as heart disease and cancer, and some medications may also trigger depressive episodes. It is also important to note that many depressive episodes occur spontaneously and are not triggered by a life crisis, physical illness or other risks.
How Long Does Depression Last?
Depending on the story behind your depression, an untreated depression can last anywhere from days to years. Studies of large numbers of people with depression show a single untreated episode can last anywhere from four months to two years.
How is Major Depression Treated?
A combination of antidepressant medication and talk therapy is most effective.
What are the Treatment Options?
If overwhelming stress has been a factor in your depression, talking about stressors and developing coping techniques and strategies can have a powerful influence in healing the nervous system. This may involve seeing a therapist, and/or attending a group designed to help you in your situation.
Many times, depression presents with symptoms that make therapy difficult, such as poor concentration, lack of motivation and energy, or hopelessness. Antidepressant medication is often very helpful in getting you tuned up enough to participate in a therapy.
Research has shown that the majority of people who have depression do best with a combination of medication and therapy. It’s like getting your car tuned and getting some coaching about driving at the same time.
Medications Prescribed for Depression
- Serotonin Reuptake Inhibitors (Prozac)
- Tricyclic antidepressants
- Alpha antagonists
- Selective norepinephrine reuptake inhibitors and aminoketones
- Monoamine (oxidase inhibitors MAO’s)
Most medications take 3-4 weeks to start working. 6-8 weeks are needed to really see changes occurring. Medication has been known to take up to 4-9 months to start making a difference. Do not stop taking these medications abruptly.
- 10-20 sessions with medication is very helpful
- Cognitive behavioral therapy helps change negative thinking
- Interpersonal Therapy: work to change/improve relationships that might contribute to worsening clinical depression
Although major depression can be a devastating illness, it is highly treatable. Between 80-90 percent of those diagnosed with major depression can be effectively treated and return to their usual daily activities and feelings. Many types of treatment are available and the type chosen depends on the individual and the severity and patterns of his or her illness.
There are three well-established types of treatment for depression: medications, psychotherapy and electroconvulsive therapy (ECT). For some people who have a seasonal component to their depression, light therapy may be useful. These treatments may be used alone or in combination.
Additionally, peer education and support can promote recovery. Attention to lifestyle, including diet, exercise and smoking cessation, can result in better health, including mental health.
It often takes two to four weeks for antidepressants to start having an effect and six to 12 weeks for antidepressants to have their full effect. The first antidepressant medications were introduced in the 1950s. Research has shown that imbalances in neurotransmitters like serotonin, dopamine and norepinephrine can be corrected with antidepressants. The FDA regularly approves different medicines; visit www.fda.gov for the most current list.
Four groups of antidepressant medications are most often prescribed for depression:
- Selective serotonin reuptake inhibitors (SSRIs) act specifically on the neurotransmitter serotonin. They are the most common agents prescribed for depression worldwide. These agents block the reuptake of serotonin from the synapse to the nerve, thus artificially increasing the serotonin that is available in the synapse (this is functional serotonin, since it can become involved in signal transmission, the cardinal function of neurotransmitters). SSRIs include fluoxetine (Prozac), sertraline (Zoloft), paroxetine (Paxil), citalopram (Celexa), escitalopram (Lexapro) and fluvoxamine (Luvox).
- Serotonin and norepinephrine reuptake inhibitors (SNRIs) are the second-most popular antidepressants worldwide. These agents block the reuptake of both serotonin and norepinephrine from the synapse into the nerve (thus increasing the amounts of these chemicals that can participate in signal transmission). SNRIs include venlafaxine (Effexor) and duloxetine (Cymbalta).
- Bupropion (Wellbutrin) is a very popular antidepressant medication classified as a norepinephrine-dopamine reuptake inhibitor (NDRI). It acts by blocking the reuptake of dopamine and norepinephrine.
- Mirtazapine (Remeron) works differently from the compounds discussed above. Mirtazapine targets specific serotonin andnorepinephrine receptors in the brain, thus indirectly increasing the activity of several brain circuits.
- Tricyclic antidepressants (TCAs) are older agents seldom used now as first-line treatment. They work similarly to the SNRIs, but have other neurochemical properties which result in very high side effect rates, as compared to almost all other antidepressants. They are sometimes used in cases where other antidepressants have not worked. TCAs include amitriptyline (Elavil, Limbitrol), desipramine (Norpramin), doxepin (Sinequan), imipramine (Norpramin, Tofranil), nortriptyline (Pamelor, Aventyl) and protriptyline (Vivactil).
- Monoamine oxidase inhibitors (MAOIs) are also seldom used now. They work by inactivating enzymes in the brain which catabolize (chew up) serotonin, norepinephrine and dopamine from the synapse, thus increasing the levels of these chemicals in the brain. They can sometimes be effective for people who do not respond to other medications or who have “atypical” depression with marked anxiety, excessive sleeping, irritability, hypochondria or phobic characteristics. However, they are the least safe antidepressants to use, as they have important medication interactions and require adherence to a particular diet. MAOIs include phenelzine (Nardil), isocarboxazid (Marplan) and tranylcypromine sulfate (Parnate).
- Non-antidepressant adjunctive agents. Often psychiatrists will combine the antidepressants mentioned above with each other (we call this a “combination”) or with agents which are not antidepressants themselves (we call this “augmentation”). These latter agents can include the atypical antipsychotic agents aripiprazole (Abilify), olanzapine (Zyprexa), quetiapine (Seroquel), ziprasidone (Geodon), risperidone (Risperdal)], buspirone (Buspar), thyroid hormone (triiodothyonine or “T3”), the stimulants (methylphenidate (Ritalin), dextroaphetamine (Aderall), dopamine receptor agonists (pramipexole (Mirapex), ropinirole (Requipp), lithium, lamotrigine (Lamictal), s-adenosyl methionine (SAMe), pindolol and steroid hormones (testosterone, estrogen, DHEA).
Individuals living with mental illness and their families must be cautious during the early stages of medication treatment because normal energy levels and the ability to take action often return before mood improves. At this time—when decisions are easier to make, but depression is still severe, the risk of suicide may temporarily increase.
There are several types of psychotherapy that have been shown to be effective for depression, including cognitive-behavioral therapy (CBT) and interpersonal therapy (IPT). Research has shown that mild to moderate depression can often be treated successfully with either of these therapies used alone. However, severe depression appears more likely to respond to a combination of psychotherapy and medication.
Three Types of Therapies
- Cognitive behavioral therapy (CBT) helps to change the negative thinking and unsatisfying behavior associated with depression, while teaching people how to unlearn the behavioral patterns that contribute to their illness.
- Interpersonal therapy (IPT) focuses on improving troubled personal relationships and on adapting to new life roles that may have been associated with a person’s depression.
- Electroconvulsive therapy (ECT) is a highly effective treatment for severe depressive episodes. In situations where medication, psychotherapy and a combination of the two prove ineffective or work too slowly to relieve severe symptoms, such as psychosis or thoughts of suicide, ECT may be considered. ECT may also be considered for those who for one reason or another cannot take antidepressant medications.
What are the Side Effects of the Medications Used to Treat Depression?
Different medications produce different side effects and people differ in the type and severity of side effect they experience. About 50 percent of people who take antidepressant medications experience some side effects, particularly during the first weeks of treatment. Side effects that are particularly bothersome can often be treated by changing the dose of the medication, switching to a different medication or treating the side effect directly with additional medications. Rarely, serious side effects such as fainting, heart problems or seizure may occur, but they are almost always treatable.
Medication Side Effects
- Tricyclic antidepressants (TCAs) cause side effects that include dry mouth, constipation, bladder problems, sexual problems, blurred vision, dizziness, drowsiness, skin rash and weight gain or loss.
- Monoamine oxidase inhibitors (MAOIs). Individuals taking MAOIs may have to be careful about eating certain smoked, fermented or pickled foods, drinking certain beverages or taking some medications because they can cause severe high blood pressure in combination with the medication. A range of other, less serious side effects occur including weight gain, constipation, dry mouth, dizziness, headache, drowsiness, insomnia and sexual side effects (problems with arousal or satisfaction).
- SSRIs and SNRIs tend to have fewer and different side effects, such as nausea, nervousness, insomnia, diarrhea, rash, agitation or sexual side effects (problems with arousal or orgasm).
- Bupropion generally causes fewer common side effects than TCAs and MAOIs. Its side effects include restlessness, insomnia, headache or a worsening of pre-existing migraine conditions, tremor, dry mouth, agitation, confusion, rapid heartbeat, dizziness, nausea, constipation, menstrual complaints and rash.
Major Depression FACT SHEET
NAMI • The National Alliance on Mental Illness • www.nami.org • 1 (800) 950-NAMI
3803 N. Fairfax Drive, Suite 100 • Arlington, VA 22203Reviewed by Dr. Ken Duckworth, NAMI Medical Director, September 2009