Differentials
Depression in adults
SIGNS / SYMPTOMS
Adults with attention deficit hyperactivity disorder (ADHD) may exhibit low self-esteem, low mood and irritability, which may be confused with depression. In ADHD, daily mood changes may represent a poorly regulated but essentially normal range of moods, rather than the more severe and prolonged low mood seen in depression.[3]
Features more suggestive of depression include significant, sustained depressed mood; loss of interest in usual activities.
Excessive guilt.
Hopelessness, suicidal ideation.
INVESTIGATIONS
Diagnosis based on DSM-5-TR criteria.
Bipolar disorder in adults
SIGNS / SYMPTOMS
Adults with attention deficit hyperactivity disorder (ADHD) may exhibit low mood, mood lability, and irritability, which may be confused with bipolar disorder. In bipolar disorder, mood instability is more severe.
Features more suggestive of bipolar disorder rather than ADHD include irritability, euphoria, depression.
Rapid speech, increased energy, decreased need for sleep.
Poor judgment: spending sprees, hypersexuality, getting into arguments/fights.
Delusions (fixed false beliefs)/hallucinations with more severe illness.
Suicidal ideation.
INVESTIGATIONS
Diagnosis based on DSM-5-TR criteria.
Borderline personality disorder
SIGNS / SYMPTOMS
Attention deficit hyperactivity disorder (ADHD) and borderline personality disorder may both include features of impulsivity, mood instability, anger outbursts, and feelings of boredom.[3]
In ADHD, impulsivity and anger are typically shorter-lived, and conflicts in relationships and suicidal preoccupation and feelings of abandonment are typically less intense. However, the two conditions may be difficult to distinguish from each other in practice due to the chronicity of symptoms in both.[3]
INVESTIGATIONS
Diagnosis based on DSM-5-TR criteria.
Autism spectrum disorder
SIGNS / SYMPTOMS
People with attention deficit hyperactivity disorder (ADHD) do not typically have the same degree of social communication difficulties as people with autism spectrum disorder (ASD).
The early developmental history is of persistent impairments in social communication; social interaction; and restricted, repetitive, and stereotyped patterns of behaviors, interests, or activities.
ADHD and ASD may co-occur.
INVESTIGATIONS
Diagnosis based on DSM-5-TR criteria.
Generalized anxiety and other anxiety disorders
SIGNS / SYMPTOMS
Anxiety disorders may cause inattention due to worry and rumination. Excessive anxiety and worry.
Panic states with autonomic arousal.
Obsessive thoughts/compulsive behaviors.
Muscle tension.
INVESTIGATIONS
Diagnosis based on DSM-5-TR criteria.
Psychosis
SIGNS / SYMPTOMS
Delusions (fixed false beliefs).
Hallucinations (most usually auditory).
Odd or strange ideas.
INVESTIGATIONS
Diagnosis based on DSM-5-TR criteria.
Specific learning disorder
SIGNS / SYMPTOMS
Circumscribed difficulties with reading, mathematics, or written expression.
Learning problems significantly interfere with academic achievement or activities of daily living.
School dropout, poor work performance.
INVESTIGATIONS
Standardized testing in reading, mathematics, or written expression.
Language disorder
SIGNS / SYMPTOMS
Circumscribed difficulties with language expression or comprehension.
Language problems significantly interfere with academic achievement or activities of daily living.
Limited vocabulary, poorly organized speech.
Pronunciation difficulties, stuttering, lisping, erratic speech rhythm.
Difficulties understanding words/specific types of words (spatial terms), sentences.
INVESTIGATIONS
Standardized testing in expressive, receptive language, or specialized functional assessment of language abilities.
Intellectual disability
SIGNS / SYMPTOMS
Known IQ of ≤70.
Deficits in numerous areas of adaptive functioning: communication, self-care, home living, social/interpersonal skills, use of community resources, self-direction, functional academic skills, work, leisure, health and safety.
INVESTIGATIONS
IQ testing: score of ≤70.
Adaptive behavior scales (Vineland Adaptive Behavior Scales and the American Association on Intellectual and Developmental Disabilities Diagnostic Adaptive Behavior Scale).
Seizure disorder
SIGNS / SYMPTOMS
Observer report of sudden loss of consciousness followed by tonic-clonic motor activity.
Observer report of altered state of consciousness accompanied by simple or complex motor activity and/or vocalizations.
Patient report of loss of consciousness, awakening with muscle aches, and/or incontinence.
Patient report of periods of lost time, disorientation/confusion.
INVESTIGATIONS
Brain MRI: usually normal in primary generalized epilepsy; may demonstrate a variety of lesions in partial epilepsy.
Electroencephalogram (EEG): during a generalized seizure, EEG demonstrates bilateral synchrony in the epileptiform activity. In partial epilepsy, a focal region of spike and sharp wave activity may be detected interictally.
Traumatic brain injury
SIGNS / SYMPTOMS
Accident/trauma history with head involvement.
Headaches.
INVESTIGATIONS
CT or MRI of the head may miss subtle traumatic brain injuries.
Studies have found single photon emission computed tomography to be more sensitive than CT or MRI in the diagnosis of traumatic brain injury.[92]
Neuropsychological testing battery.
Medication side effects
SIGNS / SYMPTOMS
Recent initiation of prescribed medication and/or over the counter medication use.
INVESTIGATIONS
Urine and/or serum drug screening positive according to medications administered.
Cautions with false-positive and false-negative results.
Substance use disorder
SIGNS / SYMPTOMS
Report of recent excessive alcohol use, illicit drug use or misuse of prescribed medications; patients may not be forthcoming in providing history.
Accidents, fights.
INVESTIGATIONS
Urine and/or serum drug screening positive.
Caution in interpreting drug screen results as false-positive and false-negatives are not uncommonly encountered. Confirmatory testing with a more sensitive test may be necessary if the initial testing result is suspect.
Sleep disorder
SIGNS / SYMPTOMS
Snoring history (patient or bed partner report).
Sudden loss of muscle tone (cataplexy).
Leg muscle soreness.
Observer report of sleepwalking.
Excessive daytime sleepiness.
INVESTIGATIONS
Sleep studies/polysomnography (physiologic/ respiratory monitoring, eye movements, electromyogram, electroencephalogram) may show patterns consistent with sleep disorder.
Hypothyroidism
SIGNS / SYMPTOMS
Tiredness.
Poor ability to tolerate cold.
Weight gain.
INVESTIGATIONS
Thyroid-stimulating hormone levels elevated in primary hypothyroidism.
Perimenopause
SIGNS / SYMPTOMS
Fatigue.
Hot flashes.
Breast tenderness.
Worsening of premenstrual syndrome.
Irregular menstrual pattern.
INVESTIGATIONS
Follicle-stimulating hormone (FSH) levels may be elevated (note: testing for FSH early in perimenopause may not be of diagnostic value because of variability in levels from day to day and during the menstrual cycle. After several months of amenorrhea, an elevated FSH level may be more predictive of impending menopause).
Age-related cognitive decline
SIGNS / SYMPTOMS
Normal aging is accompanied by a decline of cognitive abilities over time, and executive skills may be affected selectively.
It presents with memory impairment (e.g., forgetting appointments, misplacing items, memory lapses) that is not part of mild cognitive impairment (MCI) or dementia.
INVESTIGATIONS
Diagnosis involves excluding MCI or dementia.
Cognitive screening tests such as the Mini-Mental State Examination indicate increased probability of cognitive impairment.
Further testing, such as serum B12, may indicate specific etiologies, such as B12 deficiency.
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