ADHD (Attention-Deficit/Hyperactivity Disorder)

Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterized by persistent inattention, hyperactivity, and impulsivity that interferes with functioning or development. While ADHD is often discussed primarily in the context of children, it is a lifelong condition that persists into adulthood in the majority of cases. The NIMH estimates that 4.4% of U.S. adults have ADHD.

Adult ADHD: Presentations

The DSM-5 distinguishes three presentations of ADHD:

• Predominantly Inattentive — Difficulty sustaining attention, frequent careless mistakes, seeming not to listen, difficulty following through on tasks, organizational challenges, losing items, distractibility, and forgetfulness
• Predominantly Hyperactive-Impulsive — Fidgeting, difficulty staying seated, running about inappropriately, difficulty engaging in quiet activities, talking excessively, blurting out answers, difficulty waiting turn, interrupting
• Combined — Meeting criteria for both inattentive and hyperactive-impulsive presentations

In adults, hyperactivity often manifests less as physical restlessness and more as inner restlessness, chronic sense of underachievement, difficulty completing tasks, and impulsive decision-making. ADHD in women is frequently missed or diagnosed later than in men, as the inattentive presentation predominates and presents less disruptively.

ADHD and Substance Use Disorders

ADHD is a significant risk factor for substance use disorders. Research suggests that individuals with ADHD are two to three times more likely to develop SUDs than those without. The relationship is bidirectional and complex: untreated ADHD symptoms (impulsivity, sensation-seeking, difficulty with delayed gratification) increase SUD risk; stimulant medications for ADHD, properly prescribed, do not increase and may actually reduce SUD risk; and substance use can mimic or mask ADHD symptoms, complicating assessment.

Nicotine, cannabis, and alcohol are the most common substances used by individuals with ADHD. Some individuals describe using stimulants, cannabis, or alcohol as a form of self-medication for ADHD symptoms. See our article on ADHD and substance use disorders for a detailed discussion.

Diagnosis

ADHD diagnosis in adults requires a comprehensive evaluation including clinical interview, review of developmental history, self-report rating scales, and collateral information where possible. Symptoms must be present since childhood (even if not previously diagnosed), present in multiple settings, and cause significant functional impairment. Differential diagnosis must rule out mood disorders, anxiety disorders, sleep disorders, and substance use — all of which can produce ADHD-like symptoms.

Treatment

Stimulant Medications

Stimulant medications — methylphenidate (Ritalin, Concerta) and amphetamine compounds (Adderall, Vyvanse) — are the most effective pharmacological treatments for ADHD, with response rates of approximately 70–80%. They work by increasing dopamine and norepinephrine availability in prefrontal cortical circuits involved in attention and impulse control.

In individuals with co-occurring SUD, stimulant prescribing requires careful clinical judgment. Most guidelines recommend treating ADHD even in the context of SUD, as untreated ADHD worsens SUD outcomes. Extended-release formulations with lower abuse potential are generally preferred. Some clinicians prefer non-stimulant options (atomoxetine, bupropion, viloxazine) in active SUD.

Non-Stimulant Medications

Atomoxetine (Strattera), viloxazine (Qelbree), and extended-release guanfacine or clonidine are non-stimulant options with evidence for ADHD. They have no abuse potential and may be preferred for patients with co-occurring SUD or significant anxiety.

Behavioral Strategies

Cognitive-behavioral interventions adapted for adult ADHD address executive function deficits, organizational skills, time management, and emotional regulation. They are most effective in combination with pharmacotherapy.

Related: ADHD & Substance Use · Co-Occurring Disorders · Medication-Assisted Treatment