Not all symptoms of alcohol dependence are developmentally equivalent: Implications for the false-positives problem.

OBJECTIVE: Recent studies have examined the extent to which alcohol dependence (AD) criteria prospectively predict the course of AD. Critically, these studies have lacked a developmental perspective. However, the differential performance of criteria by age might indicate overendorsement in younger individuals. The current study examined AD criteria in terms of persistence and prediction of AD course and alcohol use by age in order to identify criteria that are likely to be overly endorsed by younger individuals. METHOD: The current study used longitudinal data from the National Epidemiologic Survey on Alcohol and Related Conditions to depict age differences in rates of new onset, recurrence, and persistence for each AD criterion, thereby showing how these three factors contribute to the overall age-prevalence curve of each criterion. Additionally, we tested age moderation of the predictive association between each criterion at baseline and new onset, recurrence, and persistence of syndromal AD. RESULTS: Some criteria (particularly, persistent desire or unsuccessful efforts to cut down or control drinking, and drinking despite physical/psychological problems) are both less persistent and less predictive of AD course among younger adults compared to older adults. CONCLUSIONS: These findings raise the possibility of elevated rates of false-positive AD among younger adults and suggest ways to improve the assessment of AD criteria. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Drinking beyond the binge threshold in a clinical sample of adolescents.

BACKGROUND AND AIMS: Nearly all the research conducted on high-intensity drinking has focused on college and school-based samples, with recent calls for research to understand this risky drinking pattern in non-school-based samples and across time. This study aimed to characterize predictors and consequences of non-binge drinking, age- and gender-adjusted binge drinking (level I) and drinking at levels representing two or more times (level II) and three or more times the level I binge threshold (level III) in a clinical sample of adolescents followed into young adulthood. DESIGN: Cross-sectional associations between non-binge drinking, binge levels, and negative alcohol-related consequences were examined during adolescence; prospective analyses tested whether adolescent non-binge drinking and binge levels predicted alcohol use disorder (AUD) symptoms in young adulthood and whether changes in drinking motives over time were associated with binge levels in young adulthood. SETTING: US clinical settings. PARTICIPANTS: A total of 432 adolescents (aged 12-18 years) with alcohol-related problems followed into young adulthood (aged 19-25 years). MEASUREMENTS: Life-time drinking history, Structured Clinical Interview for DSM AUDs, and Inventory of Drinking Situations. FINDINGS: Results were generally consistent with a distinction between binge level I versus levels II-III on various negative alcohol-related consequences in adolescence (Ps < 0.05) that were maintained in young adulthood (Ps < 0.01). The maintenance of relatively high endorsement of enhancement and social motives over time was associated with binge levels II-III in young adulthood (Ps < 0.001); decreases in coping motives were associated with less risky drinking in adulthood (P = 0.003). CONCLUSIONS: Among US adolescents with alcohol-related problems who were followed-up in young adulthood (aged 19-25 years), standard threshold binge drinking (five or more drinks per occasion; level I) was generally associated with fewer alcohol-related consequences and problem behaviors than binge drinking at two or more times (level II) or three or more times (level III) the standard binge threshold.

Toward more efficient diagnostic criteria sets and rules: The use of optimization approaches in addiction science.

Psychiatric diagnostic systems, such as The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), use expert consensus to determine diagnostic criteria sets and rules (DCSRs), rather than exploiting empirical techniques to arrive at optimal solutions (OS). Our project utilizes complete enumeration (i.e., generating all possible subsets of item combinations A and B with all possible thresholds, T) to evaluate all possible DCSRs given a set of relevant diagnostic data. This method yields the entire population distribution of diagnostic classifications (i.e., diagnosis of the disorder versus no diagnosis) produced by a set of dichotomous predictors (i.e., diagnostic criteria). Once unique sets are enumerated, optimization on some predefined correlate or predictor will maximally separate diagnostic groups on one or more, disorder-specific "outcome" criteria. We used this approach to illustrate how to create a common Substance Use Disorder (SUD) DCSR that is applicable to multiple substances. We demonstrate the utility of this approach with respect to alcohol use disorder and Cannabis Use Disorder (CUD) using DSM-5 criteria as input variables. The optimal SUD solution with a moderate or above severity grading included four criteria (i.e. 1) having a strong urge or craving for the substance (CR), 2) failure to fulfill major role obligations at work school or home (FF), 3) continued use of the substance despite social or interpersonal problems caused by the substance use (SI) and 4) physically hazardous use (HU)) with a diagnostic threshold of two. The derived DCSR was validated with known correlates of SUD and performed as well as DSM-5. Our findings illustrate the value of using an empirical approach to what is typically a subjective process of choosing criteria and algorithms that is prone to bias. The optimization of diagnostic criteria can reduce criteria set sizes, resulting in decreased research, clinician, and patient burden.

Adolescent Binge Drinking.

Binge drinking, commonly defined as consuming five or more standard drinks per occasion for men and four or more drinks for women, typically begins in adolescence. Adolescents, although they may drink less often, tend to consume higher quantities of alcohol per occasion compared with adults. This developmental difference in pattern of alcohol consumption may result, in part, from maturational changes that involve an adolescent-specific sensitivity to certain alcohol effects and greater propensity for risk-taking behaviors, such as binge drinking. Adolescent binge drinking is associated with a range of acute alcohol-related harms, some of which may persist into adulthood. The prevalence of binge drinking, including high-intensity drinking (i.e., 10 or more and 15 or more drinks per occasion), has declined among adolescents in recent years. Overall, however, the proportion of youth who engage in binge drinking remains high. This article reviews the definition and prevalence of binge drinking in adolescence, trajectories of binge drinking and their correlates, and implications for prevention.

Algorithm Analysis of the DSM-5 Alcohol Withdrawal Symptom.

BACKGROUND: Alcohol withdrawal (AW) is an important clinical and diagnostic feature of alcohol dependence. AW has been found to predict a worsened course of illness in clinical samples, but in some community studies, AW endorsement rates are strikingly high, suggesting false-positive symptom assignments. Little research has examined the validity of the DSM-5 algorithm for AW, which requires either the presence of at least 2 of 8 subcriteria (i.e., autonomic hyperactivity, tremulousness, insomnia, nausea, hallucinations, psychomotor agitation, anxiety, and grand mal seizures), or, the use of alcohol to avoid or relieve these symptoms. METHODS: We used item and algorithm analyses of data from waves 1 and 2 of the National Epidemiologic Survey on Alcohol and Related Conditions (current drinkers, n = 26,946 at wave 1) to study the validity of DSM-5 AW as operationalized by the Alcohol Use Disorder and Associated Disabilities Interview Schedule-DSM-IV (AUDADIS-IV). RESULTS: A substantial proportion of individuals given the AW symptom reported only modest to moderate levels of alcohol use and alcohol problems. Alternative AW algorithms were superior to DSM-5 in terms of levels of alcohol use and alcohol problem severity among those with AW, group difference effect sizes, and predictive validity at a 3-year follow-up. The superior alternative algorithms included those that excluded the nausea subcriterion; required withdrawal-related distress or impairment; increased the AW subcriteria threshold from 2 to 3 items; and required tremulousness for AW symptom assignment. CONCLUSIONS: The results indicate that the DSM-5 definition of AW, as assessed by the AUDADIS-IV, has low specificity. This shortcoming can be addressed by making the algorithm for symptom assignment more stringent.

Adolescent Executive Dysfunction in Daily Life: Relationships to Risks, Brain Structure and Substance Use.

During adolescence, problems reflecting cognitive, behavioral and affective dysregulation, such as inattention and emotional dyscontrol, have been observed to be associated with substance use disorder (SUD) risks and outcomes. Prior studies have typically been with small samples, and have typically not included comprehensive measurement of executive dysfunction domains. The relationships of executive dysfunction in daily life with performance based testing of cognitive skills and structural brain characteristics, thought to be the basis for executive functioning, have not been definitively determined. The aims of this study were to determine the relationships between executive dysfunction in daily life, measured by the Behavior Rating Inventory of Executive Function (BRIEF), cognitive skills and structural brain characteristics, and SUD risks, including a global SUD risk indicator, sleep quality, and risky alcohol and cannabis use. In addition to bivariate relationships, multivariate models were tested. The subjects (n = 817; ages 12 through 21) were participants in the National Consortium on Alcohol and Neurodevelopment in Adolescence (NCANDA) study. The results indicated that executive dysfunction was significantly related to SUD risks, poor sleep quality, risky alcohol use and cannabis use, and was not significantly related to cognitive skills or structural brain characteristics. In multivariate models, the relationship between poor sleep quality and risky substance use was mediated by executive dysfunction. While these cross-sectional relationships need to be further examined in longitudinal analyses, the results suggest that poor sleep quality and executive dysfunction may be viable preventive intervention targets to reduce adolescent substance use.

Screening for Underage Drinking and Diagnostic and Statistical Manual of Mental Disorders, 5th Edition Alcohol Use Disorder in Rural Primary Care Practice.

OBJECTIVE: To examine the National Institute on Alcohol Abuse and Alcoholism Youth Guide alcohol frequency screening thresholds when applied to Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5) diagnostic criteria, and to describe alcohol use patterns and alcohol use disorder (AUD) characteristics in rural youth from primary care settings. STUDY DESIGN: Adolescents (n = 1193; ages 12 through 20 years) visiting their primary care practitioner for outpatient visits in six rural primary care clinics were assessed prior to their practitioner visit. A tablet computer collected youth self-report of past-year frequency and quantity of alcohol use and DSM-5 AUD symptoms. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were determined. RESULTS: For early adolescents (ages 12 through 14 years), 1.9% met DSM-5 criteria for past-year AUD and ≥3 days with alcohol use in the past year yielded a screen for DSM-5 with optimal psychometric properties (sensitivity: 89%; specificity: 95%; PPV: 37%; NPV: 100%). For middle adolescents (ages 15 through 17 years), 9.5% met DSM-5 AUD criteria, and ≥3 past year drinking days showed optimal screening results (sensitivity: 91%; specificity: 89%; PPV: 50%; NPV: 99%). For late adolescents (ages 18 through 20 years), 10.0% met DSM-5 AUD criteria, and ≥12 past year drinking days showed optimal screening results (sensitivity: 92%; specificity: 75%; PPV: 31%; NPV: 99%). The age stratified National Institute on Alcohol Abuse and Alcoholism frequency thresholds also produced effective results. CONCLUSION: In rural primary care clinics, 10% of youth over age 14 years had a past-year DSM-5 AUD. These at-risk adolescents can be identified with a single question on alcohol use frequency.

Solitary cannabis use in adolescence as a correlate and predictor of cannabis problems.

BACKGROUND: Most adolescent cannabis use occurs in social settings among peers. Solitary cannabis use during adolescence may represent an informative divergence from normative behavior with important implications for understanding risk for cannabis problems. This longitudinal study examined associations of adolescent solitary cannabis use with levels of cannabis use and problems in adolescence and in young adulthood. METHODS: Cannabis using-adolescents aged 12-18 were recruited from clinical programs (n=354; 43.8% female; 83.3% Caucasian) and community sources (n=93; 52.7% female; 80.6% Caucasian). Participants reported on cannabis use patterns and diagnostic symptoms at baseline and multiple follow-ups into young adulthood. RESULTS: Compared to social-only users, adolescent solitary cannabis users were more likely to be male and reported more frequent cannabis use and more DSM-IV cannabis use disorder (CUD) symptoms. Regression analyses showed that solitary cannabis use in adolescence predicted CUD symptom counts in young adulthood (age 25) after controlling for demographic variables and the frequency of adolescent cannabis use. However, solitary adolescent cannabis use was no longer predictive of age 25 CUD symptoms after additionally controlling for adolescent CUD symptoms. CONCLUSIONS: Solitary cannabis use is associated with greater cannabis use and problems during adolescence, but evidence is mixed that it predicts young adult cannabis problems.

Course of alcohol symptoms and social anxiety disorder from adolescence to young adulthood.

BACKGROUND: There is limited knowledge of the course of social anxiety disorder (SAD) from adolescence into adulthood, and how SAD and alcohol use disorder (AUD) symptoms change together over time. The current study examined how persistent and adolescent-limited SAD relate to alcohol symptom trajectories across adolescence and into adulthood, as well as gender differences in the course of SAD and AUD symptoms. METHODS: Participants were 788 youth (ages 12 to 18 at the baseline assessment; 46.2% female; 80.5% White) recruited from the community (n = 220) and from clinical programs (n = 568). Youth completed clinical interviews on their lifetime history of AUD symptoms and SAD at baseline and were followed through age 25. Multivariate polynomial growth mixture modeling was used to estimate developmental trajectories for SAD and AUD symptoms separately, then together in a dual trajectory model. Gender differences were examined using a classify-analyze approach. RESULTS: Three SAD trajectory classes were identified: adolescent-limited (15%), persistent (6%), and no SAD (79%). For AUD symptoms, 5 trajectories were identified: severe (10%), moderate (22%), remitting (18%), young adult onset (22%), and stable low (28%). Those with a history of SAD were about twice as likely to be in the severe AUD symptom class compared to those without a history of SAD. Compared to those with persisting SAD, those in the adolescent-limited SAD class were more likely to belong to the stable low AUD trajectory. Compared to males with SAD, females with SAD were less likely to be in the moderate AUD symptom class and were more likely to be in stable low and young adult onset AUD symptom classes. CONCLUSIONS: A history of SAD was associated with membership in the severe AUD trajectory group. The association of gender with SAD and AUD differed depending on developmental period. Future research should examine whether treating SAD in early adolescence may prevent subsequent AUD symptoms.

Personality, negative affect coping, and drinking alone: a structural equation modeling approach to examine correlates of adolescent solitary drinking.

AIMS: This study examined the personality traits of negative emotionality and constraint and the ability to resist drinking during negative affective states as correlates of solitary drinking in adolescence. We hypothesized that higher levels of negative emotionality and lower levels of constraint would predict solitary drinking and that these relationships would be mediated by the ability to resist drinking in response to negative emotions. DESIGN: Structural equation modeling was used to fit a path model from the personality traits of negative emotionality and constraint to solitary drinking status through intermediate effects on the ability to resist drinking during negative emotions using cross-sectional data. SETTING: Clinical and community settings in Pennsylvania, USA. PARTICIPANTS: The sample included 761 adolescent drinkers (mean age = 17.1). MEASUREMENTS: Adolescents completed the Lifetime Drinking History, the Multidimensional Personality Questionnaire, the Constructive Thinking Inventory and the Situational Confidence Questionnaire. FINDINGS: The path model provided a good fit to the data. The association between trait negative emotionality and solitary drinking was fully mediated by adolescents' ability to resist drinking during negative affective states (b = 0.05, P = 0.01). In contrast, constraint had a direct effect on solitary drinking (odds ratio (OR) = 0.79, b = -0.23, P<0.01), as well as an indirect effect through the ability to resist drinking during negative affective states (b = -0.03, P = 0.02). CONCLUSIONS: The ability to resist drinking while experiencing negative feelings or emotions may be an important underlying mechanism linking trait negative emotionality (a tendency toward depression, anxiety and poor reaction to stress) and constraint (lack of impulsiveness) to adolescent solitary drinking.

A longitudinal study of insomnia and other sleep complaints in adolescents with and without alcohol use disorders.

BACKGROUND: Sleep disturbances are both common and well-characterized in adults with alcohol use disorders (AUDs), but have received little study in adolescents with AUDs. Furthermore, a handful of studies suggest that sleep complaints are a risk factor for AUDs. However, no published studies have yet examined the longitudinal course of sleep complaints in adolescents with AUDs; in particular, it remains unclear how persistent AUD-associated sleep complaints are in this age group, and what types of sleep complaints are most relevant to alcohol-use symptoms. We investigated these questions in a 5-year longitudinal study of adolescents with and without AUDs at baseline. METHODS: Participants were 696 adolescents (age 12 to 19) from a longitudinal study at the Pittsburgh Adolescent Alcohol Research Center. At baseline, 347 participants had a current AUD (AUD+), while 349 had no current or past AUD (AUD-). We examined sleep and alcohol involvement at baseline as well as 1-, 3-, and 5-year follow-up visits. Sleep variables included self-reported insomnia and hypersomnia, as well as variability in weekday-weekend sleep duration, all at baseline. Covariates included sex, age, current alcohol symptoms, and depression severity. RESULTS: The AUD+ group reported more overall sleep disturbance at baseline, including greater insomnia and hypersomnia complaints, and greater variability in weekday-weekend sleep duration. Group differences in insomnia and hypersomnia complaints persisted to the 5- and 3-year follow-ups, respectively. In the AUD- group, greater insomnia complaints at baseline predicted an increase in alcohol symptoms at the 1-year follow-up, while greater variability in sleep duration at baseline predicted an increase in alcohol symptoms at the 3- and 5-year follow-ups. CONCLUSIONS: These results complement previous findings in other samples, indicating that insomnia and other sleep problems are a chronic predicament for adolescents with AUDs. The findings also suggest that sleep disturbances may place adolescents without AUDs at an elevated risk of developing alcohol problems.

Serotonin Transporter Genotype Linked to Adolescent Substance Use Treatment Outcome through Externalizing Behavior.

Meta-analyses suggest that the serotonin transporter linked polymorphic region (5-HTTLPR) short (S) allele, relative to the long (L) allele, is associated with risk for alcohol dependence, particularly among individuals with early onset antisocial alcoholism. Youth in substance use treatment tend to show antisocial or externalizing behaviors, such as conduct problems, which predict worse treatment outcome. This study examined a pathway in which 5-HTTLPR genotype is associated with externalizing behavior, and the intermediate phenotype of externalizing behavior serves as a link between 5-HTTLPR genotype and substance use treatment outcome in youth. Adolescents (n = 142) who were recruited from addictions treatment were genotyped for 5-HTTLPR polymorphisms (S and LG carriers vs. LALA), assessed for externalizing and internalizing behaviors shortly after starting treatment, and followed over 6-months. 5-HTTLPR genotype was not associated with internalizing behaviors, and was not directly associated with 6-month substance use outcomes. However, 5-HTTLPR genotype was associated with externalizing behaviors (S and LG > LALA), and externalizing behaviors predicted alcohol and marijuana problem severity at 6-month follow-up. Results indicated an indirect (p < 0.05) and non-specific (i.e., both alcohol and marijuana severity) effect of 5-HTTLPR genotype on youth substance use treatment outcomes, with externalizing behaviors as an important linking factor. Adolescents in substance use treatment with low expressing (S and LG) 5-HTTLPR alleles and externalizing behavior might benefit from intervention that addresses serotonergic functioning, externalizing behaviors, and substance use to improve outcomes.

Truth or consequences in the diagnosis of substance use disorders.

AIMS: This commentary critically evaluates the use of substance-related negative psychosocial and health consequences to define and diagnose alcohol and other substance use disorders. METHODS: Narrative review. RESULTS: The consequences of substance use cause much suffering and are major public health and economic problems. However, there are a number of conceptual and measurement problems with using consequences as diagnostic criteria for substance disorders. Data indicate that substance-related consequences introduce systematic bias and degrade the validity of diagnostic systems. CONCLUSIONS: Negative psychosocial and health consequences of substance use should play a fundamentally reduced role in modern diagnostic systems for, and definitions of, addictive disorders.

Solitary Alcohol Use in Teens Is Associated With Drinking in Response to Negative Affect and Predicts Alcohol Problems in Young Adulthood.

Adolescent solitary drinking may represent an informative divergence from normative behavior, with important implications for understanding risk for alcohol-use disorders later in life. Within a self-medication framework, we hypothesized that solitary alcohol use would be associated with drinking in response to negative affect and that such a pattern of drinking would predict alcohol problems in young adulthood. We tested these predictions in a longitudinal study in which we examined whether solitary drinking in adolescence (ages 12-18) predicted alcohol-use disorders in young adulthood (age 25) in 466 alcohol-using teens recruited from clinical programs and 243 alcohol-using teens recruited from the community. Findings showed that solitary drinking was associated with drinking in response to negative affect during adolescence and predicted alcohol problems in young adulthood. Results indicate that drinking alone is an important type of alcohol-use behavior that increases risk for the escalation of alcohol use and the development of alcohol problems.

Drinking frequency as a brief screen for adolescent alcohol problems.

OBJECTIVE: Routine alcohol screening of adolescents in pediatric settings is recommended, and could be facilitated by a very brief empirically validated alcohol screen based on alcohol consumption. This study used national sample data to test the screening performance of 3 alcohol consumption items (ie, frequency of use in the past year, quantity per occasion, frequency of heavy episodic drinking) in identifying youth with alcohol-related problems. METHODS: Data were from youth aged 12 to 18 participating in the annual National Survey on Drug Use and Health from 2000 to 2007. The screening performance of 3 alcohol consumption items was tested, by age and gender, against 2 outcomes: any Diagnostic and Statistical Manual, Fourth Edition alcohol use disorder symptom ("moderate"-risk outcome), and a diagnosis of Diagnostic and Statistical Manual, Fourth Edition alcohol dependence ("high"-risk outcome). RESULTS: Prevalence of the 2 outcomes increased with age: any alcohol use disorder symptom ranged from 1.4% to 29.2%; alcohol dependence ranged from 0.2% to 5.3%. Frequency of drinking had higher sensitivity and specificity in identifying both outcomes, compared with quantity per occasion and heavy episodic drinking frequency. For both outcomes, results indicate the utility of similar cut points for drinking frequency for males and females at each age. Age-specific frequency cut points, however, are recommended for both moderate- and high-risk outcomes to maximize screening performance. CONCLUSIONS: Drinking frequency provides an empirically supported brief screen to efficiently identify youth with alcohol-related problems.

Greater prevalence of proposed DSM-5 nicotine use disorder compared to DSM-IV nicotine dependence in treated adolescents and young adults.

AIMS: Compared to DSM-IV nicotine dependence, proposed DSM-5 nicotine use disorder (NUD) would lower the threshold from three to two symptoms, and increase the number of criteria used for diagnosis from seven to 11. The impact of the proposed changes on nicotine disorder prevalence and the concurrent validity of diagnostic criteria were examined. DESIGN: Cross-sectional survey to compare DSM-IV and proposed DSM-5 algorithms. SETTING AND PARTICIPANTS: Adolescent (n = 179) and young adult (n = 292) past-year cigarette users recruited from addictions treatment. MEASUREMENTS: Semi-structured clinical interview to evaluate DSM-IV nicotine dependence, and 10 of the 11 proposed DSM-5 NUD criteria; 30-day time-line follow-back; and the Fagerström Test for Nicotine Dependence (FTND). FINDINGS: Prevalence of proposed DSM-5 NUD (two-symptom threshold) was much higher (adolescents: 68.7%, young adults: 86.0%) than DSM-IV nicotine dependence (33.0% and 59.6%, respectively), although prevalence of DSM-5 severe NUD (four-symptom threshold) was similar to DSM-IV nicotine dependence. Concurrent validity analyses in both samples indicated consistent support for DSM-5 severe NUD diagnosis (four symptoms) but not for the moderate NUD (two symptoms) diagnosis, which had modest relations with only FTND score. IRT analyses indicated strong support for the new craving item, but not for the proposed interpersonal problems and hazardous use items. CONCLUSIONS: The proposed DSM-5 nicotine use disorder criteria have substantial limitations when applied to adolescents and young adults, and appear to have low concurrent validity.

A comparison of the concurrent and predictive validity of three measures of readiness to change alcohol use in a clinical sample of adolescents.

The authors compared 3 measures of readiness to change alcohol use commonly used in clinical research and practice with adolescents: the Readiness Ruler, the SOCRATES (subscales of Recognition and Taking Steps), and a Staging Algorithm. The analysis sample consisted of 161 male and female adolescents presenting for intensive outpatient alcohol-abuse treatment who reported current alcohol use at the initial assessment. Evidence for concurrent validity was assessed by computing simple correlations of each readiness measure with the other 3 and of each readiness measure with drinking behavior (percentage of days abstinent [PDA] and drinks per drinking day [DDD], respectively, in the last 30 days) at the start of treatment and at the 6-month follow-up assessment. Evidence for predictive validity was based on percentage of independent variance accounted for by each of the readiness measures in predicting drinking behavior at 6 months from the start of treatment, and then in predicting drinking behavior at 12 months from the readiness assessment at 6 months. The results showed that all but Recognition had good concurrent validity, the Readiness Ruler score showed consistent evidence for predictive validity, and the Staging Algorithm showed good predictive validity for DDD at 6 and 12 months. For the 82 participants with an alcohol-use disorder diagnosis, the findings for the Ruler and Recognition were similar, but the Staging Algorithm had poorer prediction of DDD at 12 months, and Taking Steps was a better predictor of 6- and 12-month PDA and DDD. Research and clinical implications of the findings are discussed.