Schizophrenia, which affects 2 million to 3 million people in the U.S., causes hallucinations, delusions and disorganization. Left untreated, the disease can cause a significant loss in quality of life, including unemployment and estrangement from loved ones. But many people with schizophrenia can control the disorder and live without symptoms for several years if they consistently take prescribed antipsychotic medication, typically a daily pill.

The problem is that many people don’t continue taking their medication once their symptoms improve.

Now, a UCLA study has found that people who took a long-acting injectable form of risperidone - one given every two weeks - had a substantially lower risk for the symptoms returning than people who took the daily medication as a pill.

The study, which will be published June 24 in the journal JAMA Psychiatry, concluded that doctors should consider prescribing the long-lasting injectable medication much earlier in the course of treatment than they typically do today.

“We know that not taking antipsychotic medication is the single greatest modifiable risk factor for psychotic symptoms returning,” said Kenneth Subotnik, an adjunct professor of psychiatry at the UCLA Semel Institute for Neuroscience and Human Behavior and the study’s first author, adding that patients who have only recently developed the disease are especially susceptible to not taking their medication daily.

Although long-acting medications have been around since the 1970s, most previous studies have focused on patients who had experienced schizophrenia for many years. In those patients, the long-acting medications were not always a better alternative. The UCLA study focused specifically on patients who had recently developed the disorder.

“Individuals with a single episode of schizophrenia who have responded well to antipsychotic medication, even if they do understand they have a mental disorder, very often doubt whether medication continues to be necessary,” said Keith Nuechterlein, a UCLA professor of psychiatry and senior author of the study.

schizophrenia " align="right" /> The researchers followed 83 people recently diagnosed with schizophrenia for a one-year period. Half were given the daily oral form of risperidone and the others were given the long-acting injectable form. All interventions were given as part of the UCLA Aftercare Research Program.

The researchers found that patients taking the injectable medicine were much more likely to stick with their treatment than patients taking the oral form, and that the injectable did a better job of controlling psychotic symptoms. During the 12-month period, just 5 percent of those taking the injectable medication had their psychotic symptoms return, versus 33 percent of those taking the pill.

In addition, Subotnik said, the benefits appear to be greater than when given after individuals have had the disorder for many years, which indicates that the long-acting injectable should be offered to patients earlier in the course of schizophrenia.

Subotnik said another benefit of the injectable is that - because it’s administered at a doctor’s office rather than taken at home - doctors can more easily track whether patients are regularly taking the medication.

“Because of that, we had nearly perfect adherence to the long-acting form of risperidone,” he said.