Bipolar I Disorder is a severe psychiatric illness characterized by extreme mood fluctuations, involving episodes of both mania and major depression. Sometimes referred to in society as “manic-depressive illness,” this disorder affects not only mood but also cognition, behavior and social functioning in a profound way. Although Bipolar I Disorder typically begins between the ages of 18 and 30, it may also appear earlier and most often follows a chronic course.

Manic episodes manifest with euphoria, excessive energy, reduced need for sleep and impulsive behaviors, while depressive episodes present with sadness, anhedonia (inability to feel pleasure), guilt and suicidal ideation. These two poles may sometimes follow one another and sometimes appear simultaneously as mixed features.

DSM-5 Diagnostic Criteria for Bipolar I Disorder

According to DSM-5, the diagnosis of Bipolar I Disorder is established by the presence of at least one manic episode. This manic episode significantly impairs functioning, may require hospitalization or may include psychotic features.

Criteria for diagnosing a manic episode:

• The presence of a distinct period of abnormally and persistently elevated, expansive or irritable mood lasting at least one week
• During this period, at least three symptoms (four if the mood is irritable) must accompany:
  • Inflated self-esteem or grandiosity
  • Decreased need for sleep
  • Increased talkativeness or pressure to keep talking
  • Flight of ideas or racing thoughts
  • Distractibility
  • Increase in goal-directed activity or psychomotor agitation
  • Engagement in activities with high potential for painful consequences (such as excessive spending, risky sexual behaviors)

A manic episode alone is sufficient for diagnosis, independent of the presence of depression. However, most individuals also experience depressive episodes over time.

What Are the Symptoms of Bipolar I Disorder?

In Bipolar I Disorder, symptoms are grouped into two poles: mania and depression. Both phases significantly affect an individual’s occupational, academic, family and social life.

Symptoms of Mania:

• Exaggerated self-confidence and grandiose ideas
• Excessive cheerfulness or euphoria
• Markedly decreased need for sleep (for example, feeling energetic after only two hours of sleep)
• Rapid and continuous speech
• Accelerated thought processes, speech shifting quickly from topic to topic
• Tendency toward risky behaviors (reckless driving, uncontrolled spending, risky sexual behaviors)
• Excessive planning and starting multiple projects simultaneously

Symptoms of Depression:

• Persistent sadness, emptiness or hopelessness
• Loss of interest and pleasure
• Low energy and fatigue
• Sleep disturbances (hypersomnia or insomnia)
• Appetite changes and weight loss or gain
• Difficulty with concentration and decision-making
• Thoughts of death or suicide

What Are the Causes of Bipolar I Disorder?

The etiology of bipolar disorder is complex and explained by the interaction of genetic, neurobiological and environmental factors.

Genetic predisposition is strong: The risk is as high as 10–25% in individuals with a first-degree relative with bipolar disorder. Concordance rates in monozygotic twins range between 40–70%.

At the neurobiological level, dysregulation of neurotransmitters such as dopamine, serotonin and norepinephrine has been linked to mood changes. Increased dopaminergic activity is observed in manic episodes, while serotonergic and noradrenergic deficits are noted during depressive episodes. Additionally, dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis, with excessive cortisol production in response to stress, plays a key role in the pathophysiology of bipolar disorder.

Environmental stressors such as childhood trauma, family conflicts, substance use (particularly stimulants), seasonal changes and irregular sleep-wake cycles may trigger episodes.

What Are the Risk Factors?

Factors increasing the risk of developing Bipolar I Disorder include:

• Genetic predisposition (family history of bipolar disorder or depression)
• Childhood emotional or physical trauma
• Stressful life events (divorce, job loss, migration)
• Substance and alcohol use
• Severe sleep disturbances
• Disruption of circadian rhythms

How Is Bipolar I Disorder Diagnosed?

The diagnostic process involves detailed psychiatric evaluation and clinical history. Based on DSM-5 diagnostic criteria, the duration, frequency and functional impact of symptoms are assessed.

In the differential diagnosis, borderline personality disorder, schizophrenia spectrum disorders, attention deficit hyperactivity disorder (ADHD) and substance-induced psychotic conditions must be considered. If necessary, laboratory tests, brain imaging and neuropsychological assessments may be employed.

The presence of a full manic episode is critical for diagnosis. Unlike hypomania, a full manic episode is required to establish the diagnosis of Bipolar I Disorder.

How Is Bipolar I Disorder Treated?

Treatment of Bipolar I Disorder aims to alleviate symptoms, prevent episodes and reduce relapses. Management should be multidisciplinary, involving both pharmacological and psychosocial approaches.

Pharmacological Treatment:

• Mood stabilizers: Lithium, valproate and carbamazepine are among the most frequently used medications. Lithium is particularly effective for mania and suicide risk.
• Antipsychotics: Second-generation antipsychotics such as risperidone, olanzapine and quetiapine are often preferred for controlling manic episodes.
• Antidepressants: May be used in depressive episodes, but should always be combined with mood stabilizers, as monotherapy increases the risk of mania.
• Sleep regulators: Benzodiazepines or sedatives may be used short-term during episodes to ensure sleep.

Psychoeducation and Psychotherapy:

• Educating patients and families about the illness improves treatment adherence.
• Cognitive Behavioral Therapy (CBT) is particularly effective in improving functioning during depressive episodes.
• Family therapy is important for regulating relationships and reducing stressors.

Social Rehabilitation:

• Support services should be provided to maintain occupational, educational and social functioning.
• Structured lifestyle interventions regarding sleep regulation and stress management are recommended.

Hospitalization (When Necessary):

• In severe manic or depressive episodes, or when there is a risk of suicide or harm to others, hospitalization may be required.
• During hospitalization, medication adjustments are made and safety is ensured.

Impact on Daily Life

Bipolar I Disorder may have devastating effects on work and personal life. During episodes, social relationships may deteriorate, jobs may be lost and education may be disrupted. Particularly in manic phases, risky decisions (such as quitting a job impulsively, excessive spending, risky sexual behaviors) may lead to long-term consequences.

Depressive episodes may result in neglect of self-care, social isolation, hopelessness and suicide attempts. Research shows that approximately 20% of patients with bipolar disorder attempt suicide, and around 6% die by suicide.

Bipolar I Disorder can be managed with regular monitoring and appropriate treatment. However, discontinuation of treatment or irregular medication use increases the risk of relapse. For this reason, individuals require lifelong monitoring and support.