Gender, assigned sex at birth, and gender diversity: Windows into diagnostic timing disparities in autism.

LAY ABSTRACT: Later autism diagnosis is associated with risk for mental health problems. Understanding factors related to later autism diagnosis may help reduce mental health risks for autistic people. One characteristic associated with later autism diagnosis is female sex. However, studies often do not distinguish sex assigned at birth and gender identity. Gender diversity may be more common in autistic relative to neurotypical people, and autism is more common in gender-diverse populations. We studied age at autism diagnosis by sex assigned at birth, gender identity, and gender diversity (gender-diverse vs cisgender) status, separately. We studied three separate autistic samples, each of which differed in how they were diagnosed and how they were recruited. The samples included 193 persons (8.0-18.0 years) from a research-recruited academic medical center sample; 1,550 people (1.3-25.4 years) from a clinic-based sample; and 244 people (18.2-30.0 years) from a community-enriched sample. We found significant differences in the clinic-based and community-enriched samples. People assigned female sex at birth were diagnosed with autism significantly later than people assigned male at birth. People of female gender were diagnosed significantly later than people of male gender. Gender-diverse people were diagnosed significantly later than cisgender people. Sex assigned at birth, gender identity, and gender diversity may each show unique relationships with age of autism diagnosis. Differences in how autistic people are diagnosed and recruited are important to consider in studies that examine sex assigned at birth or gender identity. More research into autism diagnosis in adulthood is needed.

Increased anticholinergic medication use in middle-aged and older autistic adults and its associations with self-reported memory difficulties and cognitive decline.

Many commonly used prescription and over-the-counter medicines have potent anticholinergic (AC) effects. Among older adults, AC medications are associated with cognitive impairment and risk for cognitive disorders, including Alzheimer's disease. Collectively, the impact of AC medications is known as anticholinergic cognitive burden (ACB). Because of the high rates of co-occurring medical and psychiatric conditions, autistic adults may have high AC exposure and, thus, may experience elevated ACB. However, no research has characterized AC exposure or examined its associations with cognitive outcomes in autistic adults. Autistic adults (40-83 years) recruited via Simons Powering Autism Research's (SPARK) Research Match service self-reported their medication use (N = 415) and memory complaints (N = 382) at Time (T)1. At T2, 2 years later, a subset of T1 participants (N = 197) self-reported on decline in cognition. Medications were coded using two scales of AC potency. A high proportion (48.2%-62.9%, depending upon the AC potency scale) of autistic adults reported taking at least one medication with AC effects, and 20.5% to 26.5% of autistic adults reported clinically-relevant levels of AC medication (potency ≥3). After controlling for birth-sex, and age, hierarchical linear regression models showed total ACB scores and AC potency values of ≥3 predicted greater memory complaints. Logistic regression models showed that AC medicines at T1 were associated with self-reported cognitive decline at follow-up 2 years later. Understanding AC medications-including potentially earlier AC polypharmacy-and their impacts on cognition (e.g., dementia risk) in autistic adults is warranted.

AgRP neurons coordinate the mitigation of activity-based anorexia.

Anorexia nervosa (AN) is a debilitating and deadly disease characterized by low body mass index due to diminished food intake, and oftentimes concurrent hyperactivity. A high percentage of AN behavioral and metabolic phenotypes can be replicated in rodents given access to a voluntary running wheel and subject to food restriction, termed activity-based anorexia (ABA). Despite the well-documented bodyweight loss observed in AN human patients and ABA rodents, much less is understood regarding the neurobiological underpinnings of these maladaptive behaviors. Hunger-promoting hypothalamic agouti-related peptide (AgRP) neurons have been well characterized in their ability to regulate appetite, yet much less is known regarding their activity and function in the mediation of food intake during ABA. Here, feeding microstructure analysis revealed ABA mice decreased food intake due to increased interpellet interval retrieval and diminished meal number. Longitudinal activity recordings of AgRP neurons in ABA animals exhibited a maladaptive inhibitory response to food, independent of basal activity changes. We then demonstrated that ABA development or progression can be mitigated by chemogenetic AgRP activation through the reprioritization of food intake (increased meal number) over hyperactivity, but only during periods of food availability. These results elucidate a potential neural target for the amelioration of behavioral maladaptations present in AN patients.