Scientists have long recognized that many psychiatric disorders tend to run in families, suggesting potential genetic roots. Such disorders include autism, attention deficit hyperactivity disorder (ADHD), bipolar disorder, major depression and schizophrenia.
One of the most highly genetically inherited psychiatric disorders is bipolar disorder which may affect as much as 1-4% of the population. Bipolar disorder is characterized by periods of depression followed by periods of abnormally elevated mood (mania/hypomania).
Certain mental disorders tend to run in families, and having a close relative with a mental disorder could mean you are at a higher risk. If a family member has a mental disorder, it does not necessarily mean you will develop one. Many other factors also play a role.
You might worry that you could develop or 'catch' the same illness as your ill parent – but you cannot catch a mental illness from anyone. People might say 'it runs in families' or talk about the genetics or genes causing the illness.
Studies on twins and close family members have found that genetics play a role at a rate of 30-50% . Similar to depression, the genes that influence the development of anxiety aren't fully understood.
Five major mental illnesses — autism, attention deficit-hyperactivity disorder, bipolar disorder, major depressive disorder and schizophrenia — appear to share some common genetic risk factors, according to an examination of genetic data from more than 60,000 people worldwide (The Lancet, online Feb. 28).
Most psychiatric disorders are highly heritable; the estimated heritability for bipolar disorder, schizophrenia, and autism (80% or higher) is much higher than that of diseases like breast cancer and Parkinson disease. Having a close family member affected by a mental illness is the largest known risk factor, to date.
50% of mental illness begins by age 14, and 3/4 begin by age 24.
Past studies have reported that offspring of affected mothers have a higher risk of schizophrenia than the offspring of affected fathers; however, other studies found no such maternal effect [Gottesman and Shields, 1976].
The exact causes of schizophrenia are unknown. Research suggests a combination of physical, genetic, psychological and environmental factors can make a person more likely to develop the condition. Some people may be prone to schizophrenia, and a stressful or emotional life event might trigger a psychotic episode.
Bipolar disorder is frequently inherited, with genetic factors accounting for approximately 80% of the cause of the condition. Bipolar disorder is the most likely psychiatric disorder to be passed down from family. If one parent has bipolar disorder, there's a 10% chance that their child will develop the illness.
Many individuals with bipolar disorder have relatives with other mood, anxiety, and psychotic disorders (such as depression or schizophrenia). These disorders may run in families in part because they share some genetic risk factors with bipolar disorder.
The most common are anxiety disorders major depression and bipolar disorder.
The risk for schizophrenia has been found to be somewhat higher in men than in women, with the incidence risk ratio being 1.3–1.4. Schizophrenia tends to develop later in women, but there do not appear to be any differences between men and women in the earliest symptoms and signs during the prodromal phase.
Results: In patients with schizophrenia, MR imaging shows a smaller total brain volume and enlarged ventricles. Specific subcortical regions are affected, with reduced hippocampal and thalamic volumes, and an increase in the volume of the globus pallidus.
childhood abuse, trauma, or neglect. social isolation or loneliness. experiencing discrimination and stigma, including racism. social disadvantage, poverty or debt.
The outward signs of a mental illness are often behavioral. A person may be extremely quiet or withdrawn. Conversely, they may burst into tears, have great anxiety or have outbursts of anger. Even after treatment has started, someindividuals with a mental illness can exhibit anti-social behaviors.
Each illness has its own symptoms, but common signs of mental illness in adults and adolescents can include the following: Excessive worrying or fear. Feeling excessively sad or low. Confused thinking or problems concentrating and learning.
Several basic modes of inheritance exist for single-gene disorders: autosomal dominant, autosomal recessive, X-linked dominant, and X-linked recessive. However, not all genetic conditions will follow these patterns, and other rare forms of inheritance such as mitochondrial inheritance exist.
They estimated the heritability of conscientiousness, agreeableness, neuroticism, openness to experience, and extraversion to be 44%, 41%, 41%, 61%, and 53%, respectively.