LAS VEGAS – Individuals with intellectual disability experience behavioral and psychiatric illness at higher rates than the general population, according to Bryan H. King, MD.

“Increasingly, these individuals are showing up in all of our clinical practices,” Dr. King said at an annual psychopharmacology update held by the Nevada Psychiatric Association. “In this area, it’s not so much that the population doesn’t experience psychiatric illness, but the diagnosis can be challenging because the presentation of symptoms may be different. For someone who can’t articulate whether they’re feeling anxious, fearful, or nervous, it’s more challenging to make a diagnosis.”

Dr. Bryan H. King, University of California, San Francisco

Dr. Bryan H. King

Early in his psychiatry career, Dr. King led a study that set out to examine the relationship between reason for referral and subsequent DSM-III-R diagnosis in institutionalized individuals with severe to profound mental retardation (Am J Psychiatry. 1994 Dec;151[12]:1802-8). He and his associates found that these individuals were being referred to psychiatrists largely because of disruptive behaviors, including acting out, aggression, property destruction, and self-injurious behaviors. “It’s a minority of the population that’s referred for concerns about internalizing disorders,” said Dr. King, professor of psychiatry at the University of California, San Francisco.

More than 10 years ago, researchers from the University of North Carolina at Chapel Hill compared health disparities between adults with developmental disabilities in North Carolina and adults in the state with other disabilities and adults without disabilities (Public Health Rep. 2004;114[4]:418-26). They found those in the developmental disability group had a similar or greater risk of having high blood pressure, cardiovascular disease, diabetes, and chronic pain, compared with nondisabled adults. In addition, 24% of adults in the developmental disability group reported having either no one to talk to about personal things or often felt lonely.

A more recent, large national study found that, compared with adults with no autism diagnoses, those diagnosed with autism had significantly increased rates for all psychiatric disorders, including depression, anxiety, bipolar disorder, obsessive-compulsive disorder, schizophrenia (a more than 20-fold increased rate), and suicide attempts (Autism. 2015;19[7]:814-23). In addition, nearly all medical conditions such as obesity and dyslipidemia were significantly more common in adults with autism.

Results from a separate study of 371 adults with intellectual disabilities found that 40% had at least one mental health disorder and 45% had at least one moderate or severe behavior problem (Soc Psychiatry Psychiatr Epidemiol. 2016;51:767-76). In addition, the highest ratios of unmet to met need were found with respect to sexuality issues and with respect to mental health problems.

Once a diagnosis is made, Dr. King said patients who have developmental disabilities should be treated in the same way as patients who do not. “There is a tremendous amount of heterogeneity in this population,” he said. “If you are confident that you have someone before you who has depression, the treatment for depression is going to proceed in the same ways it does for someone without the condition. Let that guide the way for medications you are going to use.”

In a recent edition of Current Opinion in Psychiatry, authors Na Young Ji, MD, and Robert L. Findling, MD, reviewed current evidence-based pharmacotherapy options for mental health problems in people with intellectual disability (Curr Opin Psychiatry. 2016;29:103-25). Their five key points were:

1. “Antipsychotics, particularly risperidone, appear to be effective in reducing problem behaviors associated with intellectual disability.

2. “For attention-deficit/hyperactivity disorder symptoms, methylphenidate has been shown to be effective, and atomoxetine and alpha-agonists might be beneficial.

3. “Lithium might be effective in reducing aggression. Evidence for the use of antiepileptic drugs, anxiolytics, and naltrexone for management of problem behaviors is insufficient to draw conclusions.

4. “Antidepressants are often poorly tolerated and do not appear to be effective in decreasing repetitive or stereotypic behaviors associated with intellectual disability.

5. “Melatonin appears to improve sleep in people with intellectual disability.”

Dr. King noted that the data for using lithium in people with intellectual disability “are very old. There’s been nothing recent to help us fine-tune the indications.” He said naltrexone is among the best studied in this population, “especially for self-injurious behavior. The two large placebo-controlled trials were negative. In my own clinical experience, I have not seen it helpful.”

Dr. King disclosed that he has received research funding from the National Institutes of Health, Janssen, and Roche. He also is a consultant for Care Management Technologies and Neurotrope.