Mental disorder

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at March 15, 2016
StartDiseasesMental disorder

With approximately one in every four adults affected by a mental disorder, it is crucial that people be aware of the causes and symptoms of the most common mental disorders. The majority of mental disorders are characterized as mood disorders, anxiety disorders, personality disorders, substance-related disorders, or psychotic disorders.

Through the delivery of interviews and standardized tests, mental health professionals can diagnose mental disorders and recommend a treatment plan that corresponds to the level of severity of the diagnosis.


Definition & Facts

A mental disorder is a condition that affects a person’s behavior, mood or thought processes. There are over 450 different mental disorders. The majority of these disorders can be grouped into one of the following five general categories:

  • Mood disorders
  • Anxiety disorders
  • Substance-related disorders
  • Psychotic disorders
  • Personality disorders

Mood disorders, such as major depressive disorder and bipolar disorder, encompass the largest percentage of diagnosed mental disorders. Anxiety disorders include disorders such as social phobias, panic disorder, and generalized anxiety disorder.

Substance-related disorders include disorders characterized by a dependence upon alcohol or narcotics. Psychotic disorders, such as schizophrenia and delusional disorder, are often severe and involve the presence of hallucinations or delusions that are present for six months or longer. Personality disorders, such as borderline personality disorder, are characterized by deeply ingrained maladaptive behaviors that are often resistant to therapy.

Symptoms & Complaints

Symptoms of mental disorders range from mild to severe and may be life-threatening at times. Substance-related disorders are marked by the development of dependence on alcohol or drugs. For instance, a person with alcohol use disorder may find that he or she requires more and more alcohol in order to avoid alcohol withdrawal. The use of drugs or alcohol often begins to interfere with work or school activities and may affect a person’s interpersonal relationships.

Symptoms of mood disorders may include manic behavior, extended periods of sadness, and feelings of worthlessness. People with major depressive disorder may experience suicidal thoughts. Anxiety disorders, on the other hand, may be marked by prolonged racing thoughts, hypervigilance or excessive worrying. Sleep disturbances may also occur.

Symptoms of psychotic disorders include delusions, hallucinations or incoherent speech. The symptoms of personality disorders can be a bit more difficult to recognize, but many personality disorders are marked by problematic interpersonal relationships and rigidity in behaviors and routines.


The majority of mental disorders are caused by genetic factors, biological factors, environmental factors, physical injury or the existence of another preexisting mental disorder. In some cases, a combination of factors may be responsible for the development of a mental disorder.

For instance, people may be at an increased risk for alcohol use disorder because the disorder runs in their families. However, the disorder may actually develop as a result of social influences, such as constant exposure to alcoholic beverages in the home or within peer groups.

Like substance-related disorders, personality disorder can develop as a result of both genetic and environmental factors. Certain psychotic disorders such as schizophrenia are also influenced by genetic factors. For example, a person has a 40 to 65 percent chance of developing schizophrenia if he or she has an identical twin with the disorder.

While mood disorders may also have a genetic component, they may also be triggered by a particular event or circumstance in their environment, such as a death in the family or stress brought on by an increased work load.

Diagnosis & Tests

The first step towards accurately diagnosing a mental disorder is to conduct a psychological evaluation. A psychological test typically begins with a clinical interview during which a licensed clinical professional obtains information about a person’s background. Also included in the clinical interview are questions regarding the nature and frequency of reported symptoms.

A clinical interview provides valuable information regarding a person’s personal life, familial background, and the person’s mental state. The clinical interview also provides a mental health professional with the opportunity to assess a person’s intellectual capacity and the ability to perform basic tasks.

In addition to the clinical interview, one of a number of psychological tests may be administered. These tests are designed to screen for the presence of mood disorders, personality disorders and psychoses. Some mental health professionals may also administer an intelligence test if a learning disability or intelligence deficiency is suspected during the clinical interview.

Treatment & Therapy

The treatment of a mental disorder will depend upon a person’s particular diagnosis, age, and severity of the disorder. In most cases, mental disorders are treated with psychotherapy, psychiatric medications or a combination of medication and psychotherapy.

Medication and psychotherapy are prescribed to patients within an inpatient setting or an outpatient setting. People diagnosed with a severe or acute mental disorder often receive inpatient treatment, which involves spending a specified number of days and nights in a hospital or specialty clinic.

Schizophrenia is an example of a severe mental disorder that usually requires at least one course of inpatient treatment to ensure that hallucinations are brought under control. People with less severe diagnoses usually receive outpatient treatment.

With outpatient treatment, patients can usually proceed with their regular daily activities during the day and attend therapy sessions in the evenings. Outpatient treatment is appropriate for highly functioning individuals or people with less severe diagnoses such as dysthymic disorder.

Prevention & Prophylaxis

The prevention of mental disorders is not always possible, especially given the fact that some individuals may be genetically predisposed to develop mental health disorders.

However, there are measures that can be taken to reduce the incidence of mental disorders and to thwart their emergence. Below are five steps that are helpful in the prevention of mental disorders:

  • Receive a regular medical checkup from a primary care provider.
  • Limit exposure to substance use and other counterproductive behaviors.
  • Make every effort to control environmental stressors.
  • Learn to recognize the warning signs and symptoms of mental disorders.
  • Seek professional help if symptoms of a mental disorder begin to develop.

By following these recommendations, individuals can play a key role in the prevention of mental disorders.