I recently found out my friend has a mental disorder and I'm not sure what to think about it. I'm looking for information on how I can help her!
Was she properly diagnosed by a professional? Such disorders need to be diagnosed by a mental health professional.
Yes, she was. What do you think causes people to experience mental disorders?
Sadly, the cause of having a mental disorder are sometimes unclear. There are so many factors involved.
Oh, I see. What are some treatments for mental disorders? 
The first step would be to get an assessment done somewhere like a psychiatric hospital by a psychiatrist, psychologist and/or a clnical social worker. There are psychometric tests that can be done, or simple observation and questioning.
I really hope she gets the help she needs! Maybe for now, I'll just make sure that I'm there for her if she needs me.
Mental disorder
A mental disorder, also called a mental illness or psychiatric disorder, is a behavioral or mental pattern that causes significant distress or impairment of personal functioning. Such features may be persistent, relapsing and remitting, or occur as a single episode. Many disorders have been described, with signs and symptoms that vary widely between specific disorders. Such disorders may be diagnosed by a mental health professional.
The causes of mental disorders are often unclear. Theories may incorporate findings from a range of fields. Mental disorders are
Personal life Personal health.
Since the beginning of her career, Halsey has been open about her personal health; in 2015, speaking of her career, she stated "I'm just this fucked-up stoner kid who made it".
Halsey has bipolar disorder. She was diagnosed with this mental disorder at the age of 17, and said that her mother also has it. At that age, Halsey attempted to commit suicide, which is what led to her diagnosis and a 17-day admission to a psychiatric hospital.