Mental health: What's normal and what's not?

ROCHESTER, Minn. — When a student writes dark, violent stories, when a harried adult yells at a store clerk, when a neighbor stops doing household chores — are these symptoms of mental illness?

MayoClinic.com provides an overview of how health care providers distinguish and diagnose mental health issues and mental illness. Sometimes, it's fairly clear-cut, such as when people with schizophrenia report hearing voices, or when someone suffers from an addiction.

Other times, what's "normal" is less clear. When a child or young adult carries out school violence, for example, is it simply a normal person committing a horrific crime, or the actions of a person suffering from mental illness?

There's a broad range of what is considered normal mental health, and there's no X-ray, blood test or other straightforward physiological tools to diagnose mental illness.

• Mental health: What's normal, what's not
• School violence: An interview with a Mayo Clinic specialist

Diagnosing mental illness

Health care providers diagnose mental illness using many sources of information and indicators, including behaviors, feelings, thoughts and physiologic responses, to determine normal mental health or when treatment for mental illness is needed. They consider:

The patient's perspective: Patients may feel hopeless or discouraged or report they are no longer able to perform day-to-day tasks, or function at work or school.

Other perspectives: Sometimes, patients don't realize that they have a mental illness. Observers, such as family members and close friends, may be able to provide a more accurate assessment of the patient's behavior, thoughts or functioning.

Duration and severity of symptoms: While it's normal for people to feel sadness at the end of a relationship, it's not normal when people lose all interest in daily life after a breakup. Yelling at a store clerk once could be the sign of a bad day. But being frequently abusive or violent indicates an anti-social personality disorder.

The Diagnostic and Statistical Manual of Mental Disorders, a book published by the American Psychiatric Association, details signs and symptoms of 300 types of mental disorders. Providers use this resource to match their findings to a disorder.

Even if the line between mental health and mental illness is a bit murky, defining mental illness and honing in on a diagnosis are important. The insurance industry relies on a diagnosis to determine insurance coverage, and a diagnosis is needed to determine appropriate treatments. The good news is that, once a person is diagnosed, there are many options for effective treatment.

• Personality disorders
• Defining mental illness: An interview with a Mayo Clinic specialist