Symptoms and Treatments for Major Depressive Disorder

Experts estimate that 5% of adults worldwide suffer from depression. In the United States, roughly 21 million adults will experience an episode of depression or major depressive disorder at some point in their life.  

Written records of depression date back as far as the 4th century BCE, when Hippocrates identified it as a physiological disorder. As one of the leading causes of disability worldwide, clinical depression is much more complex than recurring feelings of sadness. 

Related: Out of Darkness podcast CE series 

Is it sadness or major depressive disorder? 

Patients will often conflate the word depression with feelings of sadness or grief, but they are not equivalent. Though grief can be profound, people experiencing these emotions can “climb out of it.” It is rarely easy. It takes time. Grieving is, after all, a process. Patients who experience clinical depression, on the other hand, often describe their feelings with a metaphor: “I’ve fallen into a hole and I can’t get out.”  

For those experiencing depression, the feelings of sadness are inescapable. Whether through medication, psychotherapy, or both, many clinicians and mental health professionals view their role as offering a ladder to their patients to help them climb out of that hole. 

A widespread illness 

Dr. Reg Williams, nurse practitioner and Professor Emeritus at the School of Nursing and Psychiatry at University of Michigan, has worked with countless patients experiencing depression throughout his career. “It’s profound, the number of people that experience depression,” he said. “When I talk about this topic, you’d be amazed how many people tell me, oh my goodness, I suffered depression or I’ve had depression in my past.”  

What Dr. Williams found notable was how rarely his patients were able to connect their symptoms with depression. Instead, they thought their inability to pull themselves out of a persistent dark mood simply meant they were lazy or weak.  

“That’s often how they describe their behavior,” Dr. Williams said. “And in reality, they’re suffering depression.” 

The cost of depression 

Depression is a costly illness, not only mentally and physically, but economically. In the latest out of a 30-year research program tracking the impact of major depressive disorder (MDD), researchers put the economic burden of MDD among U.S. adults at an estimated $326 billion in 2020. That’s a nearly 35% increase in only ten years, up from $236.6 billion in 2010. 

This cost covers everything from direct medical expenses, treating comorbidities, suicide-related costs, and the overall impact on workplace productivity.  

The pandemic only added to the cost. Starting in 2020, researchers and healthcare professionals saw a steep increase in cases of mental illness and depression, especially in younger people. In a 2022 study, the World Health Organization estimated that anxiety and depression rose 25% worldwide in the first year of the pandemic. 

Destigmatizing depression 

There is encouraging news. “In terms of stigmatization, I really seen a difference between older generations and younger people,” said Dr. Williams. “Younger people are much more willing to be open about their depression, tell their friends, etc. During my parents’ era, you didn’t even mention it.” 

While there are positive trends, however, many patients may still blame themselves for what they perceive as their own weakness. “I’ve said it to patients a number of times,” said Dr. Williams. “‘You have an illness, not a weakness.’ It’s so important that they recognized that this is an illness, no different than any other physiological illness they might suffer.” 

Diagnostic criteria for major depressive disorder 

There are several key factors to pay attention to when evaluating patients with MDD, says Dr. Williams. They may include: 

  • A depressed mood 
  • Loss of interest in activities formerly enjoyed 
  • Weight gain or weight loss 
  • Insomnia or hypersomnia 
  • Psychomotor agitation 
  • Slowed thinking 
  • Fatigue or loss of energy 
  • Feelings of worthlessness or excessive guilt 
  • Difficulty concentrating 
  • Substance or alcohol abuse  
  • Recurrent thoughts of suicide 

Related: Facts and Myths About Suicide podcast CE series 

If patients experience five or more of these or other significant symptoms within a two-week period, that points toward a diagnosis of depression.  

“Depression is an all-body illness, and so patients may also exhibit gastrointestinal symptoms like stomachaches, or headaches,” said Dr. Williams. “They have a lower stress threshold, too, so when they experience stress, it will get to them very, very quickly.” 

Interconnected systems, interconnected symptoms 

Not all symptoms of major depressive disorder manifest physically, or even psychologically. Some shadows of depression are cast in social spheres as well.  

“I’ve had a number of patients come into treatment, not because they thought they were depressed, but because they were having such difficulty in their marriage,” said Dr. Williams. “Some patients will get into risky behaviors. Or one [behavior] I see often is social withdrawal. They’ll draw away from their friends, not return phone calls, not return emails. And this becomes a vicious cycle.” 

Patient evaluation 

For a healthcare professional assessing a patient in a clinical setting without knowledge of their baseline benchmarks, some of these symptoms may be hard to decipher. They may appear to be part of the patient’s personality. 

With the patient’s permission, bringing family members into the conversation may be a wise step in these cases. 

If you or someone you know is struggling with clinical depression, we encourage you to seek help with a counselor nearest you, or by contacting the National Alliance for Mental Health (NAMI) at 1-800-950-6264. If you or someone you know is in an immediate health crisis, you can also seek help by dialing 988.