Case debrief

GAD is one of the most common anxiety disorders

GAD is one of the highest comorbidities to occur in those suffering with adult ADHD

A win–win situation occurs in this comorbidity when the SNRI class of medications is able to treat the anxiety with its SNRI dual mechanism of action, and treat the ADHD symptoms specifically with the SNRI’s NRI mechanism

• – In this case, the patient experienced a partial ADHD and GAD clinical response, but not remission

In order not to escalate this patient’s GAD symptoms or risk addiction, stimulants were avoided by using the ADHD medication, guanfacine-ER (Intuniv)

This was added to his duloxetine (Cymbalta) and titrated to 2 mg/d

If the patient had comorbid depression (instead of GAD) and ADHD, then a stimulant augmentation might be ideal as it would be less likely to aggravate anxiety (which would not be present), and might carry with it good antidepressant and procognitive effects

In this patient, low-dose guanfacine-ER improved his attention, concentration, and anxiety to where he was deemed to be in remission from both GAD and ADHD

Take-home points

There are several ways to treat GAD

Psychotherapy, SSRI, SNRI, 5-HT1A receptor partial agonism, anti-H1 receptor antagonism, and GABA-A receptor PAM are all mechanistic ways with solid evidence bases with regard to treating GAD symptoms

Like depression, GAD can become more treatment resistant and the use of combination and augmentation strategies may be utilized in a method similar to that of treating depressive disorders, i.e., rational polypharmacy

When combining/augmenting, clinicians should use drugs with different mechanisms of action instead of redundant mechanisms, as this may theoretically increase effectiveness and avoid additive side effects

Some off-label medications may have limited data to support their use, but understanding each medication’s mechanism of action gives theoretical backing and permission to use it as long as the prescriber documents the rationale behind its use

In this case, the SGRI mechanism of tiagabine (Gabitril) would be suggestive for anxiolysis as other medications that facilitate GABA activity (i.e., BZs) help anxiety as well

Performance in practice: confessions of a psychopharmacologist

What could have been done better here?

• – Instead of using polypharmacy approaches with a limited evidence base (e.g., SGRI), consider using solid approved monotherapies earlier for GAD, such as buspirone (BuSpar), Venlafaxine-ER (Effexor-XR), duloxetine (Cymbalta), etc.

• – Instead of considering adult ADHD as a diagnosis of exclusion, evaluate this symptom complex earlier in care

  • Perhaps use of a rating scale, such as the ASRS would help

Possible action items for improvement in practice

• – Research typical comorbidities and presentations for adult ADHD patients

• – Research diagnostic rating scales and instruments that may aid in diagnosing ADHD in adults

Tips and pearls

Antihypertensives are often used in psychopharmacology practice

Prazosin, an andrenergic alpha-1 receptor antagonist, is gaining popularity for use in treating nightmares associated with PTSD

Propranolol, a beta-adrenergic receptor antagonist, has been a standard approach in treating performance-type SAD for many years

• – It may also aid in treating and preventing PTSD if used quickly after exposure to traumatic events

Clonidine and guanfacine, both adrenergic alpha-2 receptor agonists, have been used for treating childhood ADHD, off-label, for many years

• – Clonidine, especially, has been used in an off-label manner to treat agitation and insomnia associated with anxiety disorders as well

• – Slow-release preparations of clonidine and guanfacine are approved for childhood ADHD now (Kapvay and Intuniv)