How Common Are Bipolar Spectrum Disorders Among People Seeking Therapy for Depression and Anxiety?

What you need to know

• Nearly 70% of patients receiving therapy for depression and anxiety in a UK primary care service showed signs of bipolar spectrum disorders
• Patients with bipolar symptoms had more complex psychiatric histories and higher rates of anxiety disorders compared to those with only depression
• All patient groups showed similar improvements after receiving psychological therapy, regardless of bipolar symptoms

Background

Bipolar disorder is a mental health condition characterized by episodes of depression alternating with periods of elevated mood (mania or hypomania). It is often misdiagnosed as depression, which can lead to inappropriate treatment. In England, a primary care program called Improving Access to Psychological Therapies (IAPT) provides therapy for people with depression and anxiety. However, IAPT is not intended for people with severe mental illnesses like bipolar disorder.

This study aimed to determine how common bipolar spectrum disorders are among patients receiving therapy through IAPT, and to examine the characteristics and treatment outcomes of these patients.

How common are bipolar spectrum disorders in IAPT?

The researchers assessed 368 patients who were starting therapy through an IAPT service in London. They used diagnostic interviews and screening tools to categorize patients into different groups:

• Bipolar disorder type I (BD-I): 9.5%
• Bipolar disorder type II (BD-II): 20.4%
• Bipolar spectrum (BSp): 39.9%
• Unipolar major depressive disorder (uMDD): 24.7%
• Other: 5.4%

In total, 69.8% of patients showed some degree of bipolar symptoms. This is much higher than previous estimates of bipolar disorder prevalence in similar populations, which have ranged from about 15% to 50%.

What are the characteristics of patients with bipolar symptoms?

Compared to patients with only depression, those meeting criteria for bipolar disorder (BD-I or BD-II) had:

• Earlier onset of mental health symptoms
• More complex psychiatric histories
• Higher rates of anxiety disorders, obsessive-compulsive disorder, and post-traumatic stress disorder
• More frequent substance use problems
• Higher levels of childhood trauma and recent stressful life events
• More severe symptoms of personality disorders

Patients in the bipolar spectrum (BSp) group generally fell between the bipolar disorder and depression-only groups in terms of these characteristics.

How did patients respond to therapy?

Interestingly, all patient groups showed similar improvements in symptoms of depression, anxiety, and psychosocial functioning after receiving therapy through IAPT. There were no significant differences in therapy outcomes between patients with bipolar symptoms and those with only depression.

Understanding bipolar spectrum disorders

Bipolar disorder exists on a spectrum, ranging from clear-cut cases that meet full diagnostic criteria to milder forms with some bipolar features. This study used the following categories:

• BD-I: Episodes of major depression and full-blown mania
• BD-II: Episodes of major depression and hypomania (a milder form of mania)
• Bipolar spectrum: Some bipolar symptoms that don’t meet full criteria for BD-I or BD-II

It’s important to note that having some bipolar symptoms doesn’t necessarily mean a person has bipolar disorder. However, it may indicate a need for closer monitoring and different treatment approaches compared to depression alone.

Why might bipolar disorders be underdiagnosed?

Several factors can contribute to the underdiagnosis of bipolar disorders:

• People are more likely to seek help during depressive episodes than manic/hypomanic episodes
• Mild hypomanic symptoms may not be recognized as problematic
• Screening for bipolar disorder is not routinely done in primary care settings
• There can be overlap in symptoms between bipolar disorder and other conditions like borderline personality disorder or attention-deficit/hyperactivity disorder

Limitations of the study

The researchers note several limitations to their findings:

• The study was conducted at a single IAPT service in London, which may not be representative of all IAPT services or primary care settings
• The screening tools used may have overestimated the prevalence of bipolar symptoms
• The study did not assess long-term outcomes after therapy
• It’s possible that some patients already had a bipolar disorder diagnosis that wasn’t captured in the study

Implications for treatment

If these findings are replicated in other studies, they could have important implications for how psychological therapy is provided in primary care:

• IAPT services may need to consider screening for bipolar symptoms
• Therapists may need additional training to recognize and work with bipolar spectrum disorders
• Some patients with bipolar symptoms may benefit from specialized therapy approaches
• Closer collaboration between primary care and mental health specialists may be needed for some patients

However, it’s crucial to note that the similar therapy outcomes across groups suggest that many patients with bipolar symptoms can still benefit from standard IAPT therapies. Any changes to services would need to be carefully considered to avoid restricting access to helpful treatments.

Conclusions

• Bipolar spectrum disorders may be much more common than previously thought among patients seeking therapy for depression and anxiety in primary care
• Patients with bipolar symptoms often have more complex mental health presentations
• Despite this complexity, patients with bipolar symptoms showed similar improvements from psychological therapy compared to those with only depression
• Further research is needed to confirm these findings and explore their implications for primary care mental health services

This study highlights the importance of comprehensive mental health assessments and the potential value of psychological therapies for a wide range of patients, including those with bipolar spectrum symptoms. It also underscores the need for continued research to improve the detection and treatment of bipolar disorders across healthcare settings.