The Six Types of Depression, According to Science

Depression is usually diagnosed from symptoms, but people with the same diagnosis can experience the condition very differently and respond differently to treatment. A major Stanford Medicine-led study published in Nature Medicine used functional MRI (fMRI) and machine learning to investigate whether those differences could be detected in patterns of brain activity.

The researchers studied 801 people with depression and anxiety and identified six distinct brain-based patterns, often described as “biotypes.” Importantly, these are research classifications rather than six officially recognised clinical diagnoses. The findings could eventually help clinicians predict which treatments are more likely to work for an individual.

What Did the Researchers Examine?

The team examined activity and connectivity in brain circuits involved in attention, cognitive control, reward, emotional processing, salience and internally focused thought. Participants underwent scans while resting and while completing tasks involving thinking and emotion. Machine-learning methods were then used to identify recurring patterns of circuit dysfunction.

1. Default Mode Circuit Pattern

The default mode network is involved in internally focused thought, including self-reflection and mind-wandering. Disruption in this system may affect how a person processes internal thoughts and experiences.

2. Salience Circuit Pattern

The salience network helps the brain identify and respond to important emotional or sensory information. Abnormal activity in this circuit may be associated with heightened anxiety, physical symptoms and feeling overwhelmed by sensory or emotional experiences.

3. Positive Affect or Reward Circuit Pattern

This circuit is involved in pleasure, motivation, reward and social enjoyment. Reduced or altered function can be associated with anhedonia — difficulty experiencing pleasure — as well as reduced motivation and a diminished sense of reward.

4. Negative Affect Circuit Pattern

The negative affect system helps process unpleasant emotions, threats and sadness. When its function is disrupted, negative emotional reactions may become unusually intense or persistent, potentially contributing to prolonged distress.

5. Attention Circuit Pattern

The attention network helps people sustain concentration and direct mental resources toward important tasks. Disruption may contribute to difficulty focusing, maintaining attention or filtering distractions — problems that some people experience during depression.

6. Cognitive Control Circuit Pattern

The cognitive control network supports executive abilities such as working memory, planning, decision-making and regulating thoughts and behaviour. Dysfunction in this system may contribute to the “brain fog,” indecision and planning difficulties experienced by some people with depression.

Could the Biotypes Help Choose Treatment?

That is one of the most promising aspects of the research. In a subset of 250 participants, researchers compared responses to behavioural therapy and three commonly used antidepressants. Some brain patterns were associated with better responses to particular treatments, suggesting that brain-based information might eventually reduce the trial-and-error approach often used in depression care.

What the Study Does Not Mean

The six biotypes are not currently a replacement for standard psychiatric diagnosis, and an fMRI scan is not a routine test for determining a person’s “type” of depression. The findings require further replication and validation in broader populations before they can become part of everyday clinical practice.

Why the Research Matters

Depression is highly heterogeneous: two people can meet diagnostic criteria while having very different symptoms and treatment responses. If biological markers can reliably identify those differences, future care could become more precise — helping clinicians match people to therapies that are more likely to benefit them sooner.

The Bottom Line

Scientists have identified six promising brain-function patterns associated with depression and anxiety, but they should be understood as emerging research biotypes rather than six established medical diagnoses. The work represents an important step toward precision psychiatry, where treatment may one day be guided by both symptoms and measurable patterns of brain function.

Important note: Depression is a medical condition that should be assessed by a qualified healthcare professional. This article is for general information and should not be used for self-diagnosis or to change prescribed treatment.

Sources: Nature Medicine research led by Stanford Medicine; Stanford University reporting on depression biotypes.