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Should We Diagnose Depression in Stages?

Reading time | 8 mins

Al Levin, a school administrator in St. Paul, Minnesota, has experienced depression twice — but the second time was dramatically worse than the first.

He described his first bout of depression, which occurred in 2010, as “situational.” He had just gotten a major promotion, and had four young children at home, including newborn twins.

“It was kind of a house that was in chaos, as well as a difficult, challenging, new position at work,” Levin explained. After he started noticing symptoms, he went to his family doctor, who prescribed medication and recommended cognitive behavioral therapy, also called talk therapy.

Levin recalled that he started feeling better after about two months of treatment. But in 2013, he was hit with a second bout of depression that was so much worse, it made him wonder if he’d ever fully recovered from his first experience.

Depression is the leading cause of disability across the globe. According to the World Health Organization, depression affects more than 300 million people.

Many people who experience depression never receive a formal diagnosis or treatment plan, in part due to gaps in mental healthcare services.

On the other hand, some researchers and clinicians believe certain groups of patients are overdiagnosed and overtreated with depression. That can stretch the healthcare system and expose people to unnecessary treatments.

It’s also common for patients who have depression to be prescribed treatments that don’t immediately help them.

Considering the impact depression has on public health, more and more researchers are looking for solutions to these problems.

Right now, diagnosing depression tends to be a binary process — either you have depression or you don’t. Psychiatrists and other healthcare providers use established diagnostic criteria to make the decision.

But what if there was a better way to classify — and treat — depressive symptoms?

Diagnosing depression in stages might be one answer.

Some experts believe that depression should be diagnosed in stages based on the severity and frequency of symptoms. That means treatment plans could potentially be better suited to the needs of each person.

A guessing game: Where is the line between healthy and unhealthy?

Levin says symptoms in 2013 seemed to come out of nowhere. He couldn’t sleep or eat, and estimates that he lost somewhere between 40 and 60 pounds. He experienced bouts of uncontrollable crying. Socializing with friends was a struggle.

To diagnose depression, healthcare professionals typically rely on what they see and what patients tell them about their symptoms. Levin’s experiences show just how much those symptoms can vary, even for the same person.

“The standard way [to diagnose depression] is by interview by a trained clinician,” said Jonathan Flint, MD, Professor of Psychiatry and Biobehavioral Sciences at the University of California, Los Angeles (UCLA). “The diagnosis is reached on the basis of meeting some criteria, which have been agreed to over the last 50 or so years and regularly reviewed and updated.”

In the United States, standard criteria for diagnosing depressive disorders are published in the Diagnostic and Statistical Manual of Mental Disorders, which is currently in its fifth edition (DSM-5).

In order to meet the criteria for major depressive disorder (MDD), a person must experience at least five symptoms associated with MDD over a period of at least two weeks. One of those five symptoms must include depressed mood, or diminished interest or pleasure in activities.

Other potential symptoms, but not necessarily in addition to include:

  • suicidal thoughts
  • feelings of guilt or worthlessness
  • trouble concentrating or making decisions
  • sleep disturbances
  • changes in weight or appetite
  • agitated or slowed movements or speech
  • fatigue

The criteria might seem clear-cut at first glance. But depending on the symptoms, it can be hard for a clinician to tell if a person has depression or is just in an unusually long slump. Sometimes, people with depression also have poor insight into their condition — so even though they have symptoms, they may be unaware of those symptoms or underestimate how they are impacted by their depression.

Evaluating someone for depression is also complicated if that person’s difficulties seem to be related to a specific situation.

It’s not unusual for major life events — such as a birth or a tough new job — to cause stress, moodiness, and sleepless nights.

However, those same events can also be triggers for mental illness, as Levin believes they may have been for his first bout of depression.

This leads to a larger question in the field of psychiatry: Where does the line between healthy and unhealthy lie?

When that line is drawn in the wrong place, some people who need treatment might not get it. Others may get a treatment that doesn’t work or a treatment they don’t need at all.

A staged approach

In an essay published this year in PLoS Medicine, Vikram Patel, MBBS, PhD, outlined a staged model for diagnosing and treating depressive symptoms.

Patel is a psychiatrist and a professor in the Department of Global Health and Social Medicine at Harvard Medical School. He argued that the DSM-5 criteria doesn’t work well for depression because “there is no clear defining line which discriminates between the miseries of daily life from the ‘disorder’ that can benefit from a clinical intervention.”

Patel’s alternative model classifies people into four stages:

  • wellness
  • distress
  • depressive disorder
  • recurrent or refractory depressive disorder

Under this model, people with mild to moderate symptoms would no longer be diagnosed with MDD. Instead, they would be classified under the “distress” stage. They would be treated by their family doctor or community-based programs, with “low-intensity interventions.”

For example, those interventions might include peer support or web-based therapy.

People who develop severe symptoms would be diagnosed with a depressive disorder. In turn, they would be treated with more intensive therapies. If their symptoms came back or didn’t respond to treatment, they would be diagnosed with recurrent or refractory depressive disorder. At that point, they would be referred to mental healthcare providers for specialized support.

Patel suggested this model would limit overdiagnosis and better target mental health resources to people who need them most.

“The staging approach minimizes the use of medication and psychotherapy to those who are most likely to need and benefit from them, and it enables us to reach out to far more people with depressive symptoms in the population,” Patel states.

When asked about Patel’s staged model for diagnosing and treating depression, Levin said he thinks it makes sense.

“I like the idea behind it because I think there’s a continuum that people fall on with their depression,” Levin said. “Like, from 0 to 10, where do they fall? If somebody’s at a 2 and not that depressed, then maybe they’ll get by with some therapy. If they’re getting up toward a 4, then maybe they need to try some medicine and do talk therapy. And if they’re not able to get themselves out of bed, maybe it’s time for something more.”

“But part of that relies on the family doctor really knowing their own limitations and being honest about that,” he cautioned. “And how much training have family doctors really had around mental illnesses? How knowledgeable is that doctor and where do they draw that line of, ‘I need to send you on for some more intensive support?’”

When it became clear that his family doctor’s support wasn’t enough back in 2013, Levin began to see a psychiatrist. Eventually, he enrolled in a three-week-long partial hospitalization program. It helped to kick-start his recovery.

To this day, he continues to attend a support group for men with depression, even though he has been “mentally healthy for over four years.”

Patel acknowledged the challenges that primary care providers might face when trying to implement his staged model.

“It requires a much more nuanced and person-centered approach — as opposed to a one-size-fits-all approach — to the management of depressive symptoms,” he said, “which in turn requires more practitioner skill and commitment to implement effectively.”

New diagnostic tools

Whichever model they use, healthcare providers rely on what patients say about their experiences to decide who meets the criteria for MDD or other depressive disorders.

That can create challenges, because patients may be reluctant to share personal details.

The diagnostic process also involves a certain amount of subjectivity. Not surprisingly, different doctors sometimes develop different diagnoses for the same patient.

“You’re reliant on a subjective report about how someone is feeling and subjective reports about what people have experienced in their past,” Flint said. “So, it’s not very reliable. Even if you spend a lot of time training doctors on how to get that information out of the patient, you’d probably only get an agreement of about 70 percent.”

Flint suggested that more research is needed to develop tools to make the diagnostic process easier.

“The idea that we’ve come up with is to start collecting data across a whole variety of aspects of human behavior,” he said. “Even simple things, like where people are or how much they move around, can give you useful information.”

To collect this data, researchers use new technologies, such as smartphones and wearable tracking devices. In the future, more advanced tools might make the process simpler and more precise.

“For example, if I see someone who’s depressed, a classic feature is slowness of speech and alteration of tone,” Flint explained. “That’s all done so far by interviews, but we can train machines to pick up changes in your speech patterns that might indicate that you’re depressed. That might be something that a machine-learning algorithm could know before [your doctor] did, and if we had measures like that, we could probably intervene earlier.”

Researchers are also looking for biomarkers, such as substances in sweat or changes in the structures of the brain, which might make it easier to diagnose and treat depression.

Exploring new models and tools will require collaboration from many experts — including psychiatrists, family doctors, computer scientists, neuroscientists, and others.

It may take time to move beyond the DSM-5 criteria, but it’s exciting to know that radically new ways of diagnosing and treating the diverse experiences that fall under MDD are on the horizon.