Introduction

Bipolar Affective Disorder is characterized by intermittent episodes of mania and depression, with periods of remission. However, we diagnose mania even if a patient has one episode of mania because studies have revealed that these patients will invariably develop more episodes of mood disorder later. During these episodes, people with bipolar disorder exhibit disruptions in normal mood, psychomotor activity-the level of physical activity mood influences-for example constant fidgeting with mania or slowed movements with depression), circadian rhythm, and cognition. Mania can present with varying levels of mood disturbance, ranging from euphoria with "classic mania" to dysphoria and irritability. 

Psychotic symptoms such as delusions or hallucinations may occur in both manic and depressive episodes, their content and nature are consistent with the person's prevailing mood.

Differentiating Mania and Hypomania

According to the diagnostic and statistical manual, fifth edition, we distinguish mania from hypomania by:

1. The course of symptoms
   1. We can diagnose hypomania if elevated mood symptoms are present for at least four consecutive days, while
   2. We cannot diagnose mania is if they have symptoms for less than a week. 
2. Hypomania rarely impairs functioning. 
3. Psychotic symptoms do not occur in patients with hypomania. 

See Table-1 for a minimum duration of the course of symptoms we require for diagnosing the common psychiatric disorders. 

Age of onset

Late adolescence and early adulthood are peak years for the onset of bipolar disorder. 

Etiology (Causes) of Bipolar Affective disorder

Bipolar affective disorder does not have a single cause. It has a high heritability, which means heritable factors explain much of the variation in its presentation. But a lengthy list of other factors also contribute to the etiology of bipolar disorder.   

Cause of Secondary Mania

>> ICD-11 - Mortality and Morbidity Statistics-Secondary Mood Syndrome 

Several medications, substances of abuse and medical conditions can cause secondary mania.  

Medical Conditions

Several endocrine disorders, like hyper or hypothyroidism, infections, vitamin deficiencies, and present with mania-like symptoms, and we need to exclude them.

Common medications that can cause manic symptoms 

1. Antidepressants
2. Prednisone
3. Anti-parkinsonian medications 
4. Thyroxine
5. Stimulants
6. Antibiotics.

Short-Answer Questions:

A 30-year-old man with a bipolar affective disorder asked you about the risk of developing a mood disorder in his children. 

What data would inform your response? 

Genetic Epidemiology of Bipolar Affective Disorder

1. The lifetime risk of bipolar affective disorder is about 1% at baseline.  
2. The risk among the first-degree relatives of probands with bipolar affective disorder is elevated ten times as much as in the population. 
3. Among probands with Unipolar mood disorder, by a factor of two.  
4. The risk of another mood episode after experiencing a first bipolar manic episode is 90%.  
5. Over the course of 25 years, an average of ten episodes occurs. 
6. The first episode is usually depressive 
7. A manic episode occurs around five years after the first depressive episode. 
8. The age of onset is usually 17-18 years 
9. Bipolar disorder does not discriminate between genders.  
10. The risk of unipolar mood disorder is twice higher in first-degree relatives of probands with BAD 
11. The concordance rate of bipolar disorder in monozygotic and dizygotic twins is 60% and 20% respectively.
12. Studies estimate heritability at about 85%

Conclusion 

Heritability of bipolar disorder is high. The children (first-degree relatives) are at an estimated lifetime risk of 10%. The manifestation is likely to occur during adolescence or young adulthood. We cannot precisely estimate risk to individuals.