tablishing precise childhood onset retrospectively. Adult recall of childhood symptoms
tends to be unreliable, and it is bene ficial to obtain ancillary information.
Manifestations of the disorder must be presen t in more than one setting (e.g., home and
school, work). Confirmation of substantial symptoms across settings typically cannot be
done accurately without consulting informants who have seen the individual in those set-
tings. Typically, symptoms vary depending on context within a given setting. Signs of the
disorder may be minimal or absent when the individual is receiving frequent rewards for
appropriate behavior, is under close supervision,  is in a novel setting, is engaged in espe-
cially interesting activities, has consistent exte rnal stimulation (e.g., via electronic screens),
or is interacting in one-on-one situa tions (e.g., the clinician's office).
Associated Features Supporting Diagnosis
Mild delays in language, motor,  or social development are not specific to ADHD but often co-
occur. Associated features may in clude low frustration tolerance, irritability, or mood lability.
Even in the absence of a specific learning disorder, academic or work performance is often im-
paired. Inattentive behavior is associated with various underlying cognit ive processes, and in-
dividuals with ADHD may exhibit cognitive pr oblems on tests of attention, executive
function, or memory, although these tests are not suff iciently sensitive or specific to serve as di-
agnostic indices. By early adulthood, ADHD is a ssociated with an increased risk of suicide at-
tempt, primarily when comorbid with mood, conduct, or substance use disorders.
No biological marker is diagnostic for AD HD. As a group, compared with peers, chil-
dren with ADHD display incr eased slow wave electroenc ephalograms, reduced total