If you plan to apply for a U.S. temporary visa or for lawful permanent residence (a green card), you will be expected to show that you do not present a health risk to the general American public. This is one of the grounds of inadmissibility. It does not only mean showing that you are not a medical risk (as with germs or a virus), but that you are not a mental health risk.
You might not be allowed to enter or remain in the United States if you have now, or have had in the past, a mental disorder that causes you to engage in behavior that might be harmful to yourself or others.
Let's take a closer look at who might be affected by this mental health ground of inadmissibility, and when someone might be granted a visa or green card regardless of psychiatric difficulties.
The officials evaluating a visa or green card application do not simply issue denials whenever they see that someone has had mental health issues. They look in particular at:
In most cases, these determinations are made through examination by medical professionals. A medical exam is required for any immigrant visa (the type of visa that leads to a green card, for example through a U.S family member or employer).
A medical exam can also be required for a nonimmigrant (temporary) visa, if the U.S. consular officer believes it to be warranted. This might happen, for example, because the officer spotted something relevant on the applicant's police record or noticed some odd or inappropriate speech, appearance, thought-processing, or behavior during the visa interview.
Remember also that, even if the person has no medical or criminal record suggesting a mental health disorder, the consular office may ask about such things outright—and applicants are expected to answer honestly.
In performing medical evaluations on immigrants, the physicians will look to guidance from the U.S. Centers for Disease Control (CDC). The physician may also refer the applicant to specialists for follow-up evaluation.
According to the CDC guidance, the mental disorders that are most frequently associated with harmful behavior are:
This doesn't mean that other disorders won't be used as grounds of inadmissibility, however. Even anxiety disorders, which many people suffer from while leading fully functioning lives, can lead to inadmissibility, if the disorder has led to harmful behavior to the applicant or others.
Behaviors considered harmful include:
Broadly speaking, if at least 12 months have passed since the visa or green card applicant exhibited harmful behavior, and the underlying mental disorder has a favorable prognosis, the examining physician can decide that the disorder is in remission or under control. In that case, the person might not be found inadmissible after all.
Some disorders are considered less likely to be controllable than others, however. In particular, the CDC guidelines say that applicants with a history of harmful behavior associated with paraphilia or other sexual acts are almost always likely to relapse.
You might be able to request that U.S. immigration authorities overlook your mental-health ground of inadmissibility, by filing a "waiver" request. See Waivers of Health-Based Inadmissibility for U.S. Green Card Applicants for details. You will need to show that you are not at future risk of causing harmful behavior, and you might also need to have a treatment plan in place.