By Tom Insel, MD and Matthew Hirschtritt, MD, MPH

A new review of the effects of “nudging” has implications for behavior change and, perhaps, vaccination policy. A Canadian study examined a tough convergence: kids, screens and pandemic. Our dilemma of the week: what’s the best option for discharging homeless patients from psychiatric hospitals? Plus: ketamine for depression, fentanyl in drug overdoses, and more on surging mental health needs during the pandemic. Read on – and let us know if there’s an important paper we missed.

Want to Change Behavior? A Nudge May Be Better Than a Shove

Who would have thought developing a vaccine would be easier than getting people vaccinated? (Well, some people did, those who pay attention to behavioral science.) When applied to behavior change, that science offers important lessons: Our decisions are often not rational, we are influenced by implicit bias, and sometimes the best way to change behavior is not through explanation and argument but through nudging. (For a fun and powerful example of an amusing nudge, click to see the video below.)

Since the 2008 publication of Thaler and Sunstein’s book, Nudge—Improving Decisions about Health, Wealth, and Happiness, behavioral scientists have been intrigued by the use of nudges – aka “choice architecture interventions” ­– to alter behavior. A nudge is any effort to influence behavior while preserving freedom of choice. This is easier to understand with examples. Here are three types of nudges:   

Nudging with information: providing social norms. Households which regularly received a letter comparing their own energy consumption to that of similar neighbors reduced their consumption by an average of 2%.

Nudging by limiting options: changing the default. In countries which register individuals as organ donors by default (allowing them to opt-out if they so wish), the rate of donor registrations is nearly 60 percentage points higher than in countries with laws requiring people to formally agree to becoming a donor. 

Nudging by refocusing attention: decision assistance. Employees given the chance in advance to allocate part of future salary increases to retirement savings increased their average saving rates from 3.5% to 13.6%.

So nudging can be effective ­– but how effective? And for which behaviors? Stephanie Mertens and colleagues from the University of Geneva did a meta-analysis of more than 200 nudging studies. Overall, they found small to medium effect sizes, roughly comparable to the behavioral changes seen with educational campaigns or financial incentives. But important differences emerged based on the kind of nudge. Studies that changed the default – like the organ donation example ­–generally worked best. The behavior also mattered. Nudging had weak effects on financial and health behaviors but bigger effects on food consumption (perhaps we’re conditioned by the nudging of our mothers and grandmothers).

So is there a nudge to increase vaccination? Mertens and colleagues don’t discuss this, but their results would encourage the use of default conditions (opting-out not opting in) more than social norms and refocusing attention. And, oh, maybe an edible instead of an injectable vaccine? Biological science developed the vaccines but overcoming vaccine hesitancy may require applying psychological science.

The effectiveness of nudging: A meta-analysis of choice architecture interventions across behavioral domains  Proc Natl Acad Sci, Dec 30, 2021

Tradeoffs Between Safety and Length of Psychiatric Hospitalization Among Homeless Patients

At least a quarter of the 580,000 Americans who are homeless on any given night suffer from a serious mental illness like psychosis or major depression. Many end up in psychiatric hospitals, and it’s often difficult to find a safe place for them to go after discharge. One way to protect those who can’t take care of themselves is by a court appointing a conservator or guardian to oversee their care and make decisions about medical care and finances.

Hospital psychiatrists may initiate a temporary conservatorship while a longer-term placement is sought – but it takes time. And with fewer and fewer psychiatric hospital beds available, each day a patient occupies one means another person who needs a bed is left waiting, often in an emergency room.

To unpack these issues, a team led by Kristen Choi at UCLA used data for 795 adults who stayed at one safety-net psychiatric hospital between 2016 and 2018. She found that those who came to the hospital from the streets remained hospitalized nearly a month longer that those who had housing. Previously homeless patients made up only 6% of the study sample but used 41% of the total hospital days. Homeless patients for whom a conservatorship was initiated stayed in the hospital over six times longer (155 versus 26 days for the whole sample), but had a far lower risk of being unhoused at discharge than patients placed on a 30-day psychiatric hold without a conservator being appointed.

This study highlights one of the many difficult choices facing providers when a patient is discharged from a locked psychiatric hospital. From these data, it seems that when focusing on a single gravely disabled and homeless patient, conservatorship would be the safest option – but one that’s likely to increase the strain on an already overburdened system. Choi’s data remind us that not only do we need more capacity, we need to look upstream at social measures that prevent and solve homelessness in the first place. Increasing the supply of supportive and affordable housing and community-based health services is imperative.

Mental Health Conservatorship Among Homeless People with Serious Mental Illness. Psychiatric Services, October 27, 2021.

Screen Time for Kids: There’s Reason to Worry – and to Act

Photo: Shutterstock

It’s hardly news that parents are deeply worried about the impact of social media and videogames on their kid’s mental health, ­especially since the pandemic has left students spending their school days online and much of their social time in video chats or games. Still, hard data about the effects is inconsistent. Now researchers from the Hospital for Sick Children and the University of Toronto have some to offer.

A team led by Xuedi Li followed four cohorts of more than 2,000 children from May 2020 to April 2021, tracking their screen time and parents’ reports about their mental health. For younger children (mean age: 5.9 years), more time spent on TV or digital media was associated with higher levels of conduct problems and hyperactivity/inattention. Among older kids (mean age: 11.3 years), more TV or digital media time was associated with higher levels of depression, anxiety, and inattention and more time playing video games was associated with higher levels of depression, irritability, inattention, and hyperactivity. This wasn’t all about games on screens – more time spent on learning devices was also associated with high levels of depression and anxiety. And contrary to predictions, social interactions via video chat were not protective.

The results fit with pre-pandemic data linking screen time above 3 to 4 hours a day to poor mental health. Nearly all of this research is correlational, leaving questions of causality and mechanism unanswered. Nevertheless, these findings support the need for children to have face-to-face interactions and suggest that limits on screen time are important for healthy development.

Screen Use and Mental Health Symptoms in Canadian Children and Youth During the COVID-19 Pandemic JAMA Network Open, Dec 28, 2021 

Measuring Ketamine’s Antidepressant Effects in the Real World

Image: Shutterstock

Though intravenous ketamine has been used to manage pain for over 50 years, it wasn’t until 2000 that a small, randomized trial suggested that ketamine infusions might be effective for depression. In the ensuing two decades, multiple trials have demonstrated ketamine’s rapid antidepressant effect, usually within four hours of administration, but often waning within a week. Similarly, a single infusion has been associated with a rapid decrease in suicidal ideation lasting one to three days. This pattern of rapid results is promising because the effects of conventional antidepressants may take six to eight weeks to kick in.

The key weakness of most studies to date is that they examined how well ketamine performs in ideal circumstances, not how well it works in the real world. To bridge this gap, L. Alison McInnes, from the mental health company Osmind, and colleagues at Stanford University analyzed self-reported depression ratings among 537 patients who received four to eight ketamine infusions between 2016 and 2020 at 178 private-practice community clinics in 40 states. Most patients paid for KIT out of pocket; each treatment cost between $300 and $690.

Over half (54%) experienced at least a 50% drop in their depression score 14 to 31 days after their final infusion and 29% experienced remission of their depression so they became virtually asymptomatic. Nearly three-quarters of patients who felt suicidal before induction experienced a decrease in these thoughts. Even without any booster doses, nearly 80% of patients who initially responded to ketamine continued to show a response four weeks later and 60% eight weeks later. About 8% of patients reported worsened depression and 6% reported more severe suicidal ideation.

These results should be interpreted with some caveats: Only 3 months of follow-up data were available. The study didn’t control for patients’ medical and psychiatric history or the medications they’d been taking. And there may be unmeasured differences among the patients and the clinics. Still, this study adds to the growing evidence that ketamine can rapidly reduce depression that hasn’t responded to conventional treatments. Especially impressive are the lasting effects up to two months after induction.

Still, questions remain: Who will pay for these infusions, which are generally not covered by insurance? How should patients be selected? How can we ensure their safety?  How long will the effect of ketamine last? Will some patients never get off ketamine? Does it matter whether ketamine is accompanied by therapy? Research will need to address these questions as ketamine use in private clinics grows.

A retrospective analysis of ketamine intravenous therapy for depression in real-world care settings. Journal of Affective Disorders, January 11, 2022.

Four in Ten Fentanyl Deaths Involve Stimulants

Drug overdose deaths have surged during the COVID-19 pandemic. A CDC report in November noted over 100,000 overdose deaths from May 2020 to April 2021, an increase of 28.5% from the previous year. In a new report, the CDC identifies synthetic opioids, especially street fentanyl, in 64% of these overdose deaths. While the fentanyl threat is national, fatal overdoses increased most in western (94%), southern (65%), and midwestern (33%) states. Four in ten deaths also involved use of stimulants (e.g., methamphetamine, cocaine). Concurrent synthetic opioid and stimulant use complicates substance-use treatment and increases fatal overdose risk associated with synthetic opioids.

Trends in and Characteristics of Drug Overdose Deaths Involving Illicitly Manufactured Fentanyls — United States, 2019–2020. Morbidity and Mortality Weekly Report, December 17, 2021.

More Evidence of Increased Mental Health Needs During the Pandemic

Multiple reports have found a surge in mental health issues during the pandemic. Most rely on self-report data, surveys, or questionnaires. Now new findings from Relias, a private healthcare data company, compares diagnostic data and claims for behavioral healthcare in 2019 and 2020 for over 1.5 million Medicaid recipients. As expected, the number of people seeking behavioral health care spiked during the pandemic, with nearly twice as many adults diagnosed with anxiety and roughly twice as many children diagnosed with depression. At the same time, the number of visits for non-behavioral health care significantly decreased. This new report adds to the growing evidence that the pandemic has contributed to a growing mental health crisis.

Behavioral Health Diagnoses and Health Care Use Before and During the COVID-19 Pandemic Psychiatric Services, January 7, 2022


Tom Insel, MD, is a psychiatrist, neuroscientist, and former director of the National Institute of Mental Health (NIMH). He is a donor to MindSite News and chair of its Editorial Advisory Board. Dr. Insel’s financial conflict of interest statement, which includes equity and advisory roles in several early-stage mental health technology companies, can be found here.

Matthew Hirschtritt, MD, MPH, is a clinical psychiatrist with the Permanente Medical Group, Inc., a mental health services researcher with the Division of Research, Kaiser Permanente Northern California, and assistant program director of the Kaiser Permanente Oakland Adult Psychiatry Training Program. His current research focuses on identification and treatment of patients with first-episode psychosis, as well as implementation of a telehealth-based mental health evaluation and referral program.