DEAR DR. ROACH: I’ve seen a number of stories lately about people who’ve been arrested for behavior that doesn’t seem to be criminal, but the behavior is odd. Some of these people are homeless, and I wonder if they are mentally ill and aren’t taking prescribed medication.

— P.L.P.

ANSWER: Mental illness often leads to behaviors that definitely seem odd. Behaviors like hoarding, which can be found by itself or with several different mental illnesses, often affect the individual but sometimes lead to risks for others who live with them. These behaviors can lead to interactions with police that would be considered a “public nuisance.”

Mental health remains stigmatized, and there are often inadequate resources to help people with mental illnesses. This leads to a situation where there are three to six times as many people with mental illnesses in the criminal justice system than expected. People with mental illnesses are also much more likely to be homeless. Most mental health disorders are treatable, but the treatment received while a person is homeless or incarcerated is often poor.

It’s common for people with mental health disorders to stop taking their medication. These medicines can have side effects that make people feel unwell or just not themselves. Many times, I’ve seen people stop taking them while they feel well, which causes their problems to become much worse.

Substance abuse is also a major issue. Substance abuse can make any mental health condition worse, and it can be very difficult to properly diagnose a person while they are actively using recreational drugs. A prolonged hospitalization is necessary to make a diagnosis for them and receive proper treatment, but this is very expensive.

Odd behaviors in an ideal world should trigger an investigation into whether a person who has a mental health disorder is in need of treatment. In this ideal world, early treatment could lead to improvements in a person’s quality of life and prevent the homelessness or arrests that too often accompany untreated mental illnesses. Unfortunately, we live in a world that is still pretty far from this ideal one.

Dr. Roach regrets that he is unable to answer individual letters, but will incorporate them in the column whenever possible. Readers may email questions to ToYourGoodHealth@med.cornell.edu.