Prenatal alcohol exposure (PAE) may lead to fetal alcohol spectrum disorders (Hoyme et al., 2016) which include fetal alcohol syndrome (FAS), partial FAS (PFAS), alcohol-related neurodevelopmental disorder (ARND), and alcohol-related birth defects (ARBD). As a group, these disorders are associated with neurobehavioral deficits, growth deficits, facial dysmorphology, and/or other medical symptoms (Hoyme et al., 2016). Recent prevalence studies have suggested that FASD affects 1.1 to 5% of children in the U.S. (May et al., 2018), and it is one of the leading causes of birth defects and neurobehavioral deficits in children (Williams et al., 2015), even more prevalent than autism spectrum disorder (Maenner et al., 2020).
Despite these prevalence rates, diagnosis is particularly difficult due to confounding factors, such as incomplete or inaccurate self-report, lack of biomarkers, and comorbidities with other diagnoses (i.e., ADHD; Wozniak et al., 2019), and delays in diagnosis can lead to an increased risk of adverse outcomes in childhood (Streissguth et al., 2004). Diagnosis of FAS and PFAS is made, in part, based on facial dysmorphology (Del Campo & Jones, 2017) which can increase certainty of exposure and outcome. However, the majority of individuals with PAE do not manifest physical markers of their exposure (Wozniak et al., 2019), limiting the diagnostic utility of these features. Further, neurobehavioral challenges are present in individuals with PAE even in the absence of the characteristic physical features, and studies have shown that alcohol-exposed individuals with and without physical features have deficits in neuropsychological domains such as IQ, motor functioning, and learning (Mattson & Riley, 1998; Mattson et al., 1997). Neurobehavioral difficulties associated with FASD encompass cognition, behavior, and mental health. Cognitively, people with FASD experience deficits in general intelligence, executive functioning, attention, learning, memory, motor skills, and language (Mattson et al., 2019). FASD is associated with an elevated risk of mental health disorders, such as anxiety and depression (Fryer et al., 2007; Hellemans et al., 2010) as well as externalizing disorders such as attention-deficit/hyperactivity disorder, conduct disorder, and oppositional defiant disorder (Fryer et al., 2007). Some studies have shown that fewer dysmorphology features is associated with more behavioral problems (Fagerlund et al., 2011); however, other studies have shown that these symptoms occur at the same rate with and without physical features (Mattson & Riley, 2000). Therefore, creating a diagnosis that specifically reflects neurodevelopmental and mental health symptoms of PAE, rather than physical features, will increase early diagnosis and intervention, leading to fewer adverse outcomes.
In the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), an FASD diagnosis termed neurodevelopmental disorder associated with prenatal alcohol exposure (ND-PAE) was added under “Conditions for Further Study” to better detail the neurodevelopmental and mental health symptoms associated with PAE that are not captured with current FASD criteria (American Psychiatric Association, 2013, 2022; Kable et al., 2016). In contrast to other diagnoses described under the FASD diagnostic umbrella which are medical diagnoses, ND-PAE is a mental health diagnosis and is not reliant on a dysmorphology evaluation (Hoyme et al., 2016; Kable et al., 2016). In contrast to the ARND diagnosis, the ND-PAE diagnosis, which is based on deficits in neurocognition, self-regulation, and adaptive functioning, is independent of facial dysmorphology and can be made in individuals with or without FAS or PFAS (Hoyme et al., 2016). Like ARND, a diagnosis of ND-PAE requires confirmed PAE (Hoyme et al., 2016; Kable et al., 2016). The ND-PAE diagnosis also increases the number of individuals who have the expertise needed to diagnose and treat an individual with PAE.
ND-PAE criteria are categorized into three domains: neurocognitive, self-regulation, and adaptive functioning, and symptoms in all domains must first appear in childhood (American Psychiatric Association, 2013, 2022). For neurocognitive impairment (NI), impairment must be present in one of the following categories: global intellectual functioning (which is represented by an IQ or parallel assessment of 70 or below), executive functioning, learning, memory, and visual spatial reasoning. For self-regulation (SR), impairment must be seen in mood or behavioral regulation, attention, and/or impulse control. Finally, in the adaptive functioning (AF) domain, deficits must be seen in either communication (i.e., acquiring and understanding language) or social communication with one of the following: impairment in daily living or motor impairment. However, with the exception of global intellectual functioning (an IQ of 70 or below or a score of 70 or below on a similar comprehensive development assessment), the threshold for impairment in these domains is not clearly defined (Kable & Coles, 2018).
Previous studies have assessed the validity of the diagnosis and have found that the AF domain may be too restrictive (Kable & Coles, 2018). Specifically, requiring two out of four criteria for the AF domain (AF 2/4) may not be necessary, and requiring that one of the two first criteria for adaptive functioning (communication and social communication) is not supported by the literature and therefore may lead to low sensitivity, or fewer true positives (Sanders et al., 2020). Sanders et al. (2020) also evaluated construct and factorial validity of the ND-PAE diagnosis and found through principal component analysis (PCA) that symptoms only loaded on one factor, which included neurocognitive and adaptive functioning criteria. Their assessment of convergent and divergent validity showed that convergence, or the correlation among symptoms, was low among SR symptoms, specifically the correlation between mood regulation and attention symptoms (Sanders et al., 2020). Due to the unspecified impairment threshold in the DSM-5, previous studies have assessed symptom severity at 1.0, 1.5, and 2.0 standard deviations (SDs) from the mean (Kable & Coles, 2018; Sanders et al., 2020). Internal validity analyses have shown that the symptoms have a fair internal consistency at both 1.0 and 1.5 SDs (Sanders et al., 2020). However, these studies have small sample sizes (n < 58).
A recent paper by Kable et al. (2022) evaluated the ND-PAE diagnosis in a community sample of over 1000 1st-grade children (5-7y) as a part of the Collaboration on FASD Prevalence (CoFASP) study. Participants were categorized as “at-risk” if they were exposed to more than minimal (> 13 drinks per month or 2 or more drinks on one occasion) amounts of alcohol prenatally or if they exhibited physical deficits such as facial dysmorphology or growth delays. This at-risk group was compared to a no risk group, categorized as not having any PAE and no related physical deficits (i.e., growth deficits and facial dysmorphology). They assessed criteria at both 1.0 and 1.5 SDs and assessed two different AF criteria for impairment: only one AF criterion needed (AF 1) or the original AF 2/4 criteria. Memory impairment for the NI domain was not assessed because it was not measured in all of the participants of this sample. Results showed higher endorsement of the ND-PAE diagnosis using 1.0 SD than 1.5 SD as the indicator of impairment and significant differences in ND-PAE endorsement between the at-risk and control groups at 1.0 SD. In the AF domain, having one necessary criterion (AF 1) led to a significant difference between the at-risk and no risk groups in AF endorsement at both 1.0 and 1.5 SDs, in contrast to the AF 2/4 criteria, which only had a significant difference between groups at the 1.0 SD cutoff. PCA was also performed to determine categories for the symptoms, which resulted in two factors: one with self-regulation, adaptive social skills, and adaptive independent living skills, and the other with IQ, visual-spatial functioning, adaptive communication, and adaptive motor skills. The authors used receiver operating characteristic (ROC) curves to test if each item and domain contributed to discrimination in ND-PAE endorsement (sensitivity and specificity). ROC curves produce area under the curve (AUC) values with values under 0.70 considered poor and values over 0.90 considered excellent. The results indicated that having an IQ score below 70 (i.e., 2.0 SD) did not significantly contribute to the diagnosis with either AF model in either of the groups (AUC < 0.60) and that the NI domain had poor prediction of the diagnosis with either AF model at 1.0 SD (AUC < 0.70). Therefore, they assessed IQ at 1.0 and 1.5 SDs and found that global intellectual impairment better predicted ND-PAE categorization at both 1.0 and 1.5 SD levels. Overall, the endorsement for the diagnosis was low among the at-risk group, which may be because these participants were recruited from the community instead of a healthcare facility and therefore may not be experiencing symptoms at the same rate or intensity as more heavily exposed individuals. Gender also seemed to play a role, as males had higher endorsement of symptoms than females in their sample.
Additional validation for this diagnosis is needed in a larger, more heavily exposed sample. The purpose of the current study is to evaluate the ND-PAE criteria in a sample with heavier exposure and a wider age range.