To classify as clinically significant, any mental disorder must endurably impact daily function (i.e. ideally be shown to have done so for at least 6 months). In ADD/ADHD, the symptoms/signs must be generalisable to all domains of the person’s life – i.e. not occur specifically in only one setting (i.e. not be setting specific), and the symptoms should not be better accounted for by a more common disorder, such as a mood or anxiety disorder.
Dysregulation in noradrenergic and dopaminergic pathways plays a critical role in suboptimal executive functioning within prefrontal regions of the brain, which are involved in attention and memory.1
| Signs of Inattention | Signs of Hyperactivity/Impulsivity |
| Displays poor listening skills | Squirms when seated or fidgets with feet/hands |
| Loses and/or misplaces items needed to complete activities or tasks | Marked restlessness that is difficult to control |
| Sidetracked by external or unimportant stimuli | Appears to be driven by “a motor” or is often “on the go” |
| Forgets daily activities | Lacks ability to play and engage in leisure activities in a quiet manner |
| Diminished attention span | Incapable of staying seated in class |
| Lacks ability to complete schoolwork and other assignments or to follow instructions | Overly talkative |
| Avoids or is disinclined to begin homework or activities requiring concentration | Difficulty waiting turn |
| Fails to focus on details and/or makes thoughtless mistakes in schoolwork or assignments | Interrupts or intrudes into conversations and activities of others |
| Impulsively blurts out answers before questions completed |
The symptoms should have presented themselves prior to the age of 12 and, be careful that the symptoms are not simply the manifestations of oppositional behaviour. Consider the person’s functioning in the academic, social, and/or occupational setting.
Treatment is pharmacological and supportive.
stimulants: modulating increased dopamine and norepinephrine levels; effective in all age groups
Methylphenidate (Ritalin) is a synthetic CNS stimulant that can be habituating and addictive and can affect the cardiorespiratory centre in the medulla, leading to hypertensive crises among others. It is contraindicated in bipolar disorder (can precipitate a manic episode), psychosis (as it would be further destabilising), and with recent MAOI use (risks a sympathomimetic/serotonin toxidrome). Avoid it in those with glaucoma, hypertension, or heart disease, incl. congenital heart disease (e.g. long-QT syndrome), hyperthyroidism, Tourette’s (tic disorder), severe anxiety, tension, or agitation. Stimulants have caused stroke, heart attack, and sudden death. Patients need to be well screened. Adverse reactions: insomnia; aggression; anxiety; agitation; headache; tremor; palpitations; hypertension; bruxism.
short-acting: need at least bd-tid dosing.
- methylphenidate: start at 5 mg OD or BD and then increase by 5 mg every 3 days.
- dextroamphetamine: start at 2.5-5 mg OD or BD and increase by 2.5-5 mg every 3 days.
long acting::
- methylphenidate MR (Concerta): initially 18 mg mane, incr. titrate by 9 mg at weekly intervals to max. 54 mg.
- lisdexamfetamine (Vyvanse):
non-stimulants: increasing norepinephrine levels
- atomoxetine (Strattera): non-stimulant sympathomimetic (SNRI) that selectively blocks the pre-synaptic norepinephrine transporter (NET) protein, one of the monoamine transporters that affects the neurotransmission involved in hyperactivity and impulse control; 0.5 mg/kg per day increasing every 3 days to target 1.2 mg/kg per day given OD or a in a divided (BD) dose.
- guanfacine (Intuniv): this alpha2A-adrenergic agonist is indicated in children and adolescents and administered once daily starting at 1 mg and increasing by no more than 1 mg per week to maintenance of 0.05-0.12 mg/kg per day. Can cause headache, dizziness, hypotension, bradycardia, insomnia, anxiety, nightmare, aggression, suicidality, irritability, dry mouth, reduced appetite. Monitor HR, BP, Height/Weight, and for impulsive thoughts/behaviour.
clonidine: central alpha2-agonist antihypertensive used off-label for ADHD can cause depression, dizziness, orthostatic hypotension, dry mouth, GI upset, headache, fatigue. It is contraindicated in 2nd/3rd degree HB and hereditary galactose intolerance. Usual dose is 100 mcg nightly but can be given 100 mcg BD. Avoid abrupt discontinuation.
anti-depressants: these should be prescribed with extra caution in ADHD.
Much of the ADHD I see clinically does seem to cluster in families under real social and structural strain, single-parent households, high family conflict, limited stability at home. It’s tempting to read that as cause and effect: fewer boundaries, more dysregulation. But the evidence doesn’t really support that story. ADHD is highly heritable, and a good deal of what looks like an environmental effect of family structure turns out, on closer genetic study, to be confounded: parents with ADHD or related traits are themselves more likely to experience relationship breakdown, and they pass on both the genetic risk and the disrupted home environment to their children. The correlation is real; the “poor discipline causes ADHD” reading of it isn’t. What’s not in doubt is that ADHD causes real psychological distress, in the child and often in the family around them, and that used judiciously, pharmacological treatment works well.
- Del Campo N, Chamberlain SR, Sahakian BJ, Robbins TW: The roles of dopamine and noradrenaline in the pathophysiology and treatment of attention-deficit/hyperactivity disorder. Biol Psychiatry. 2011 Jun 15;69(12):e145-57. doi: 10.1016/j.biopsych.2011.02.036. Epub 2011 May 6.