Why Two People With the Same Diagnosis May Need Completely Different Treatment

Two people can walk into a psychiatric office with the same diagnosis and leave with very different treatment plans. That isn't inconsistency. It is often what good psychiatric care should look like.

Consider two successful professionals who both meet criteria for major depressive disorder.

One is sleeping ten hours a night, struggling to get out of bed, gaining weight, feeling mentally slowed, and barely generating enough energy to get through the workday.

The other is sleeping four or five hours, waking at 3 a.m. thinking about work, losing weight, feeling constantly anxious, and spending the day pushing through exhaustion while appearing completely functional to everyone around them.

On paper, both may have the same diagnosis. Clinically, they are not having the same experience. And that matters.

A diagnosis is the beginning of the formulation, not the end

Psychiatric diagnoses give us a common language. They help identify recognizable patterns of symptoms, guide treatment decisions, communicate between clinicians, and connect what someone is experiencing with an evidence base. But a diagnosis cannot tell us everything we need to know about the person who has it. Before deciding what treatment makes sense, I want to understand much more.

What do the symptoms actually look like? Depression can present with insomnia or excessive sleep, decreased appetite or increased appetite, agitation or profound slowing, severe cognitive symptoms, anxiety, irritability, loss of motivation, or some combination of these.

ADHD, anxiety disorders, bipolar disorder, and other psychiatric conditions can be equally heterogeneous.

What else is occurring at the same time? Comorbid conditions matter. So do sleep disorders, substance use, medical illnesses, hormonal changes, medications, and other factors that can contribute to psychiatric symptoms or influence treatment choices.

What has happened before? Previous medication responses are enormously useful. So are adverse effects, family psychiatric history, developmental history, previous episodes, psychotherapy experiences, and the circumstances surrounding periods when someone was doing particularly well or poorly.

What does this person's life actually require of them? This is especially relevant when treating high-performing professionals. A medication that causes cognitive dulling, significant fatigue, sexual dysfunction, weight gain, or daytime sedation may technically reduce symptoms while creating a completely different set of problems for someone whose occupation requires sustained attention, rapid decision-making, creativity, leadership, or frequent travel.

Treatment effectiveness is not simply: Did the symptom score improve? It is also:

Can this person function well in the life they actually live?

Even the treatment goal may be different

For one person, the immediate priority may be getting enough symptom relief to return to work. For another, work performance has never deteriorated. Their goal may be restoring relationships, sleeping normally, feeling emotionally present again, or no longer using every ounce of energy to maintain an outward appearance of functioning.

That is one reason I am cautious about interpreting professional success as evidence of psychiatric wellness. Some people remain extraordinarily productive while struggling significantly.

Personalized psychiatry is more than choosing a medication

Individualized treatment can include medication, psychotherapy, behavioral changes, sleep interventions, exercise, treatment of contributing medical conditions, reduction of substance use, changes in workload or environment, or sometimes a decision that medication is not the right intervention at all.

And when medication is appropriate, the diagnosis alone rarely tells us which medication is best for a particular person. The question isn't simply: “What treats depression?” It is:

“What is the most appropriate treatment for this particular person, with this particular presentation, medical history, biology, priorities, risks, and life?” Those are very different questions.

Psychiatry certainly has algorithms, guidelines, and evidence-based treatments. We need them. But the evidence has to be applied to an individual human being.

A diagnosis tells us what someone has in common with other people. Good treatment also pays attention to everything that makes them different.

Have you ever been surprised by how differently the same mental-health condition can look from one person to another?