ADHD Pathology, Diagnosis, and Treatment

A set of vocabulary flashcards covering the diagnostic criteria, comorbidities, pathophysiology, and pharmacological treatments for ADHD as presented in the lecture notes.

ADHD (Attention Deficit Hyperactivity Disorder)

A developmental disorder characterized by persistent inattention and/or hyperactivity and impulsivity that develops progressively into a constant condition.

ODD

Oppositional defiant disorder; a condition that must be distinguished from ADHD as it does not require pharmacological treatments.

DSMV Criteria for ADHD (<17 years)

Patients should show a persistent pattern of inattention and/or hyperactivity/impulsivity interfering with functioning, evidenced by at least $6$ symptoms present for at least $6$ months.

DSMV Criteria for ADHD (Adults >17 years)

Diagnosis requires a minimum of $5$ symptoms of inattention and/or hyperactivity/impulsivity.

ADHD Symptom Onset and Settings

Symptoms must start before age $12$, occur in at least $2$ settings (e.g., home and school), and be present for the past $6$ months.

Environmental Causes of ADHD

Factors including previous viral infection, stress during pregnancy, lower family income, single parenting, traumatic events, and childhood abuse.

Type 1 Diabetes Comorbidity

ADHD is more likely to be diagnosed alongside this condition; affected children develop more diabetes ketoacidosis and have higher $Hb1Ac$.

Methylphenidate (Ritalin)

A first-line psychostimulant that acts as a potent dopamine and noradrenaline uptake inhibitor with immediate effect on some symptoms.

Lisdexamfetamine Dimesylate (LDX)

A prodrug amphetamine that blocks dopamine uptake and inhibits dopamine vesicle transporters to cause massive dopamine release.

Atomoxetine

A second-line non-psychostimulant treatment; it is a very selective noradrenaline uptake inhibitor (SNRIs) with antidepressant properties that takes $6-8$ weeks for effect.

Others: Alpha-2A-Adrenergic Agonists

Drugs such as Guanfacine or Clonidine (less selective) used as antihypertensives that show therapeutic effects for ADHD after $2-4$ weeks.

Metadoxine

A treatment consisting of pyroglutamic acid and vitamin $B6$ originally used for alcohol intoxication.

Dopamine Deficit Theory

Untreated ADHD shows increased dopamine transporter availability leading to excessive reuptake, resulting in low dopamine levels in the synaptic cleft.

Neuroinflammation

One of the neurobiological system imbalances in ADHD that alters neural signalling and brain development.

Methylphenidate Release Design

Offered as a mixture of $30\%$ immediate release (rapid onset) and $70\%$ extended release (sustained effect) to mimic multiple doses and reduce rebound.

5-HT1A Receptor

A serotonin receptor where methylphenidate may have weak agonist activity, though the binding affinity is very low and considered negligible in practice.

Psychomotor slowing/Apathy

Symptoms for which methylphenidate is used off-label as an adjunct in treatment-resistant depression.

Intranasal Methylphenidate Abuse

Crushing or snorting the drug to cause rapid release of synaptic dopamine, producing effects similar to or stronger than cocaine.

Toxicity Signs (High Dose)

Psychiatric symptoms including delirium, extreme anger, aggressiveness, panic states, hallucinations, fever, and irregular heart rate.

SUD (Substance Use Disorders)

Adults previously treated with MPH have a slightly higher risk of developing these compared to untreated controls, though early/long treatment may mitigate risks.

Prodromal Phase

A phase of functional impairment and developmental delays preceding schizophrenia or bipolar disorder, where symptoms may be mistaken for ADHD.

Treating Psychosis Comorbidity

If ADHD is comorbid with schizophrenia or bipolar disorder, clinicians must treat the psychosis first to clarify symptom contribution.