This study investigated the relationship between various intrapersonal factors and the discrepancy between subjective and objective cognitive difficulties in adults with attention-deficit hyperactivity disorder (ADHD). The first aim was to examine these associations in patients with valid cognitive symptom reporting. The next aim was to investigate the same associations in patients with invalid scores on tests of cognitive symptom overreporting.

The sample comprised 154 adults who underwent a neuropsychological evaluation for ADHD. Patients were divided into groups based on whether they had valid cognitive symptom reporting and valid test performance (n = 117) or invalid cognitive symptom overreporting but valid test performance (n = 37). Scores from multiple symptom and performance validity tests were used to group patients. Using patients’ scores from a cognitive concerns self-report measure and composite index of objective performance tests, we created a subjective-objective discrepancy index to quantify the extent of cognitive concerns that exceeded difficulties on objective testing. Various measures were used to assess intrapersonal factors thought to influence the subjective-objective cognitive discrepancy, including demographics, estimated premorbid intellectual ability, internalizing symptoms, somatic symptoms, and perceived social support.

Patients reported greater cognitive difficulties on subjective measures than observed on objective testing. The discrepancy between subjective and objective scores was most strongly associated with internalizing and somatic symptoms. These associations were observed in both validity groups.

Subjective cognitive concerns may be more indicative of the extent of internalizing and somatic symptoms than actual cognitive impairment in adults with ADHD, regardless if they have valid scores on cognitive symptom overreporting tests.

To examine a possible problem of overreporting and to describe the degree of error with the International Physical Activity Questionnaire (IPAQ) short telephone protocol.

Cross-sectional study, using two different physical activity (PA) self-report protocols.

Telephone interviews about PA in Belgium.

Fifty adults who had previously been interviewed with IPAQ in a national survey.

Seventy-five per cent reported less PA with the modified procedure than with the IPAQ. Twenty-three of the 50 individuals were found to have reported some amounts of PA with the IPAQ (either walking, or vigorous or moderate PA) when they should have reported none. In total, based on their revised reports of PA, 50% fewer persons met PA recommendations than was the case with IPAQ. The overreporting could not be related to types of error-prone individuals.

Overreporting of PA in population samples is a serious problem that could be reduced by implementing procedure changes without changing the IPAQ items themselves.

To assess the influence of different standards and restrained eating on underreporting in healthy, non-obese, weight-stable young subjects.

Eighty-three young adults (20–38 years, 55 women, 28 men) were assessed under weight-stable conditions with a 7-day dietary record and the three-factor eating questionnaire by Stunkard and Messick. Resting energy expenditure (REE; indirect calorimetry) plus data derived from physical activity records (PA) (Standard 1) or REE times an activity factor (AF) (Standard 2) was used as standard for total energy expenditure (TEE). For comparison, doubly labelled water (DLW) was used to measure TEE in a subgroup of subjects.

There was an association between self-reported energy intake and Standard 2 (r = 0.72) but not with Standard 1. When compared with DLW both calculated standards were inaccurate, but Standard 2 avoided high levels of overreporting. Using Standard 2 to identify ‘severe’ underreporting (SU; as defined by a deviation of energy intake (EI) and TEE of >20%), SU was seen in 37% of all subjects. It was more frequently found in women than in men (49% of women, 14.3% of men, P < 0.05). Underreporting subjects had a reduced EI (P < 0.01) but there were no significant differences in nutritional status (body weight and height, body mass index, fat mass and fat-free mass), energy expenditure and the proportion of energy from macronutrients between normal and underreporting subjects. However, high restraint was associated with a higher degree of underreporting in the total group, whereas disinhibition had an influence only in men.

A high prevalence of SU is seen in non-obese subjects. Characteristics of eating behaviour (restraint and disinhibition) were associated with underreporting but seemed to have a different influence in men and women.