Nutritional Psychiatry: Does It Exist?

Andrew J. Rosenfeld, MD

Matt was diagnosed with ADHD combined type when he was 6 years old. Given his age, the family was reluctant to try medications, but after a couple years of parenting classes and reward charts, the parents requested a stimulant. He had significant improvement in focus and impulsivity but also reduced appetite. Now at age 13, irritability and depressive symptoms have been increasing for 9 months. Skeptical of adding another medication, his parents ask whether nutrition might be an alternative tool to treat his symptoms?

While few would argue with the foundational importance of nutrition for healthy childhood development, how to apply nutrition to mental health care becomes a much more nebulous pursuit. What a healthy diet even consists of seems to be a moving target over decades and years. Trendy research, supplements, and dietary approaches proliferate alongside appealing theories of action. In the end, weighing which intervention is effective for which disorder and at what cost becomes murky.

Yet several fundamental principles seem clear and consistent over time and across studies.

Starting early

There is reliable evidence that in the perinatal environment, nutrition sets the stage for many aspects of healthy development. These effects are likely mediated variously through the hypothalamic-pituitary-adrenal axis, the trillions of gut bacteria that make up the microbiome, gene-environment interactions, and more. Maternal malnutrition and stress prenatally puts infants at risk for not only poor birth outcomes but also psychiatric challenges throughout childhood, such as ADHD, anxiety, depression, and autism.^[1]

Intervening in the perinatal period has long-term benefits. A first step includes assessing food security, beginning with consistent access to nutritious food. It is important to inquire about the role of food and nutrition in the family’s history and culture, as well as identifying resources to support access to affordable nutrition. This can be paired with parenting interventions, such as family meals without screens. This may require scaffolding positive conversations in high-conflict family settings (see The Family Dinner Project).

Healthy diets promote mental health

If food security is achieved, what is next? Clinicians can inquire about the who, what, where, when, and why of nutrition to learn about a family’s eating habits.^[2] While randomized controlled data is very limited, both cross-sectional and longitudinal studies show that healthy diets in youth correlate with mental health – more healthy foods reducing internalizing and externalizing disorders, and more typical Western diets increasing the risk. On average, dietary interventions include higher levels of fruits and vegetables, fish, and nuts, and lower levels of processed foods.^[2] There is not evidence that restrictive diets or fasting is appropriate or safe for youth. Additionally, involving children in getting, growing, or preparing food with gradually increasing autonomy fosters self-confidence and skill development.

In those struggling with restrictive eating disorders, food is medicine – helping those with restrictive diets to develop more balanced and adequate intake for metabolic needs. Outside of diagnosable eating disorders, weight or body mass index is less of a goal or marker when it comes to mental health. Instead, look for participation in enjoyable activities, opportunities to move and rest, and a body image that supports self-care and self-confidence (see the National Institutes of Health’s We Can! Program). Creating dissonance with cultural ideals of appearance centered on thinness can prevent future eating disorders.^[3]

Nutraceutical options

Outside of eating disorders, specific foods and plants with health or medicinal properties – variously called nutraceuticals, phytoceuticals, or micronutrients – have emerging evidence in mental health. A 2022 expert academic consensus panel reviewed the literature to create clinical guidelines in this area.^[4] For major depression, adding omega-3 fatty acids to standard antidepressant treatment or standalone St. John’s wort have adequate evidence to recommend, while adjunctive probiotics, zinc, saffron, and curcumin have sufficient though less robust evidence. S-adenosyl methionine, vitamin D, and methyfolate showed only weak evidence for depression, while vitamin C, magnesium, creatine, N-acetylcysteine, folate, and monotherapy omega-3s do not have sufficient evidence to be recommended. For ADHD there was weak support for vitamin D, but no clear evidence for omega-3s, zinc, gingko, or acetyl L-carnitine. For anxiety, there is moderate evidence for ashwagandha and lavender in adults. A child psychiatry review suggests also trying chamomile for generalized anxiety based on the evidence in young adults, and underscores some data for N-acetylcysteine for OCD in particular.^[5]

Many of these nutraceuticals exhibit small or moderate effects in a limited number of trials, with generally much less data for youth, compared with adults. While the same could be said for many on- and off-label uses of psychiatric medications for kids, clinicians would be wise to consider these highly specific nutritional interventions as items on the menu of treatment options rather than stand-alone treatments.

Revisitng the case study

Reflecting on Matt’s care, his pediatrician first assessed his dietary patterns, noting late-night eating and caffeine use with minimal hydration or fiber across the day. Recommendations for keeping fruit and vegetable snacks easily accessible as well as carrying a water flask are well received. They also discuss adding omega-3 fatty acids and probiotics with his morning stimulant while he awaits a referral for cognitive-behavioral therapy in order to address his depressive symptoms and minimize medication needs.

Beyond addressing food security and balanced family meals, specific interventions may be appropriate as initial treatment adjuncts for mild and some moderate mental illness. For more intense moderate to severe illness, nutritional psychiatry may be considered in combination with treatments with stronger evidence. At a community level, clinicians can help advocate for universal school meal programs to address food security, and so-called salad bar interventions to increase fruit/vegetable uptake among school-age children.

Dr. Rosenfeld is associate professor of psychiatry and pediatrics at University of Vermont and the Vermont Center for Children, Youth, and Families, both in Burlington. He has no disclosures.

This article originally appeared on MDedge.com, part of the Medscape Professional Network.

Follow Medscape on Facebook, X (formerly known as Twitter), Instagram, and YouTube

Comments

Commenting is limited to medical professionals. To comment please Log-in.

Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.