What is the condition where patients frequently forget tasks or have difficulty keeping focus and experience short to long term memory issues?

Attention-Deficit/Hyperactivity Disorder (ADHD)

The condition you are describing—where patients frequently forget tasks they set out to do, have difficulty keeping focus, and experience short to long-term memory issues—is most consistent with Attention-Deficit/Hyperactivity Disorder (ADHD), specifically the inattentive subtype. 1

Core Diagnostic Features

ADHD diagnosis requires the presence of specific inattentive symptoms that have persisted for at least 6 months and cause clinically significant impairment in at least two settings (e.g., work and home) 1:

• Lack of attention to details/careless mistakes 1
• Lack of sustained attention 1
• Poor listener 1
• Failure to follow through on tasks (directly addresses "forgetting tasks set out to do") 1
• Poor organization 1
• Avoids tasks requiring sustained mental effort 1
• Loses things 1
• Easily distracted 1
• Forgetful (directly addresses memory concerns) 1

For the Inattentive Type diagnosis, at least 6 of these 9 symptoms must be present. 1

Critical Diagnostic Considerations

Age of Onset Requirement

The symptoms must have been present before age 7 years (though they may not have caused impairment until later in life when demands increased) 1. However, recent research has identified "late-manifestation" ADHD where symptoms become apparent in adulthood due to increased life stressors, despite the underlying condition being present earlier 2.

Severity and Impairment

The symptoms must be:

• More severe than typically observed in individuals at a comparable developmental level 1
• Causing clinically significant impairment in social, academic, or occupational functioning 1
• Not better accounted for by another mental disorder 1

Differential Diagnosis: Critical Pitfalls

A major clinical pitfall is that ADHD symptoms can closely resemble early dementia or mild cognitive impairment (MCI), particularly in adults over age 50. 3 The overlap includes:

• Inability to provide sustained attention or mental effort 3
• Difficulty organizing or multi-tasking 3
• Forgetfulness 3

Distinguishing ADHD from Dementia

Key differentiating features:

ADHD characteristics:

• Symptoms present since childhood (even if not diagnosed) 1
• Stable or fluctuating pattern rather than progressive decline 2
• Predominantly inattention-related symptoms 2
• Often triggered or unmasked by stressful life events 2
• Younger age at presentation (though can manifest later) 2

Dementia/MCI characteristics:

• Insidious onset over months to years in older adults 4
• Clear-cut history of worsening cognition by report or observation 4
• Progressive decline rather than stable symptoms 4
• May include impairment in learning and recall of recently learned information 4

In one dementia clinic study, 1.6% of patients initially suspected of having dementia (particularly early-onset Alzheimer's disease) were actually diagnosed with ADHD. 2 This highlights the importance of considering ADHD in the differential diagnosis.

Medical Conditions That Mimic ADHD

Before diagnosing ADHD, a thorough medical evaluation must rule out conditions that present with similar symptoms: 5

• Absence seizure disorder 5
• Diabetes 5
• Thyroid dysfunction 5
• Sleep deprivation 5
• Post-concussion states 5
• Inflammatory bowel disease 5
• Iron deficiency and anemia 5
• Disordered breathing 5
• Narcolepsy 4

A medical history, physical examination, and screening laboratory tests are essential to rule out these conditions. 4

Comprehensive Evaluation Requirements

The diagnosis must be based on: 1

1. Complete psychiatric evaluation with particular focus on:

   • Core ADHD symptoms starting in childhood 4
   • Information from spouse, parent, or friend (adults with ADHD often have poor insight and underestimate symptom severity) 4
   • Detailed history of drug and alcohol use (high rate of comorbid substance abuse) 4
   • Consider urine drug screen 4

2. Structured rating scales (useful but not solely diagnostic) 4:

   • Wender Parent's Rating Scale 4
   • Wender Utah Rating Scales 4
   • Brown Attention-Deficit Disorder Scale for Adults 4
   • Conners Adult ADHD Rating Scale 4

3. Rule out other psychiatric conditions in differential: 4

   • Bipolar disorder 4
   • Depression 4
   • Axis II personality disorders 4
   • Learning disabilities 4
   • Undiagnosed borderline intellectual functioning 4

Common Comorbidities

Adults with ADHD show significant comorbidities that can complicate diagnosis: 6

• Depressive disorders 6
• Anxiety disorders 6
• Substance use 6
• Oppositional defiant disorder 6
• Personality disorders 6
• Sleep problems 6
• Learning disabilities 6

Important caveat: Mood symptoms or lability resulting from ADHD itself are often mistaken for comorbid disorders. 6

Treatment Approach

FDA-approved pharmacologic treatments for adult ADHD include: 6

• Stimulants (methylphenidate, dexmethylphenidate) 6
• Atomoxetine (nonstimulant) 1, 6

Atomoxetine dosing for adults:

• Initiate at 40 mg total daily dose 1
• Increase after minimum of 3 days to target of 80 mg daily 1
• May increase to maximum of 100 mg after 2-4 additional weeks if optimal response not achieved 1
• Administered as single morning dose or divided doses (morning and late afternoon/early evening) 1

Critical consideration: Effect sizes of approved medicines at approved doses in adults are half those seen in children, and adults may need longer duration of medication effects. 6

Psychosocial interventions may be beneficial in treating both ADHD and comorbidities. 6 ADHD treatment should be part of a comprehensive program that may include psychological, educational, and social measures. 1