Diagnostic Criteria for GAD, Bipolar Disorder, and PTSD
Generalized Anxiety Disorder (GAD)
Use the GAD-7 scale as your primary diagnostic screening tool, with a cutoff score of ≥8-10 points indicating probable GAD in adults. 1, 2
Core Diagnostic Features
The pathognomonic symptom of GAD is excessive, uncontrollable worry about multiple life domains (not just a single concern), which distinguishes it from normal anxiety or cancer-related worries. 1, 3 Patients may present with "concerns" or "fears" rather than overt anxiety symptoms. 1
GAD-7 Screening Tool
The 7-item scale assesses frequency over the past 2 weeks (0=not at all, 1=several days, 2=more than half the days, 3=nearly every day): 1
- Feeling nervous, anxious, or on edge
- Not being able to stop or control worrying
- Worrying too much about different things
- Trouble relaxing
- Being so restless that it is hard to sit still
- Becoming easily annoyed or irritable
- Feeling afraid, as if something awful might happen
Severity Interpretation
- 0-4 points: Minimal/none - no functional impairment, effective coping skills present 1, 2
- 5-9 points: Mild to moderate - worries about multiple areas, fatigue, sleep disturbances, irritability, concentration difficulties, mild-to-moderate functional impairment 1, 2
- 10-14 points: Moderate to severe - symptoms interfere moderately to markedly with functioning 1, 2
- 15-21 points: Severe - marked functional impairment 1, 2
Associated Features to Document
- Family history of anxiety disorders (signals inherited vulnerabilities) 1, 3
- Prior treatment history for anxiety 1, 3
- Comorbid psychiatric disorders, particularly depression (50-60% of GAD patients have comorbid anxiety disorders) 1, 3
- Alcohol or substance use/abuse 1
- Chronic medical illnesses 1
- Physical symptoms: autonomic hyperreactivity, sleep/eating irregularities 1
Differential Diagnosis Considerations
Distinguish GAD from panic disorder, social phobia, and other specific anxiety disorders by identifying the range of worry topics beyond a single domain. 1, 3 The GAD-7 has sensitivity of 89% and specificity of 90% for GAD, with positive predictive value of 52-56% and negative predictive value of 96-97%. 1
Bipolar Disorder
Consider bipolar disorder in any patient presenting with depression, as misdiagnosis is common and antidepressant monotherapy is contraindicated in bipolar I disorder. 4
Key Diagnostic Elements
Bipolar disorders are characterized by recurrent episodes of mood elevation (mania or hypomania) and depression, with variable severity. 4 The DSM-5 includes new specifiers for mixed features and anxious distress that aid in recognizing episode severity and prognosis. 4
Manic Episode Criteria
A manic episode requires at least 1 week (or any duration if hospitalization required) of abnormally and persistently elevated, expansive, or irritable mood, plus increased goal-directed activity or energy. 4 During this period, at least 3 of the following must be present (4 if mood is only irritable):
- Inflated self-esteem or grandiosity
- Decreased need for sleep
- More talkative than usual or pressure to keep talking
- Flight of ideas or racing thoughts
- Distractibility
- Increase in goal-directed activity or psychomotor agitation
- Excessive involvement in activities with high potential for painful consequences 4
The episode must cause marked impairment in social or occupational functioning, necessitate hospitalization to prevent harm, or include psychotic features. 4
Hypomanic Episode Criteria
Hypomania involves the same symptom criteria as mania but lasts at least 4 consecutive days, represents a clear change from usual functioning, is observable by others, but does not cause marked impairment or require hospitalization and has no psychotic features. 4
Bipolar I vs. Bipolar II
- Bipolar I: At least one manic episode (may also have hypomanic or major depressive episodes) 4
- Bipolar II: At least one hypomanic episode AND at least one major depressive episode, but never a full manic episode 4
Critical Assessment Points
- Screen for substance use disorders (highly comorbid) 4
- Assess for suicidal ideation at every visit 4
- Document other mental health disorders (rates are elevated) 4
- Identify environmental triggers: seasonal light changes, shift work, circadian disruption 4
- Evaluate for chronic medical comorbidities 4
Mixed Features Specifier
Document when depressive and manic/hypomanic symptoms occur simultaneously during the same episode, as this affects treatment decisions (antidepressant monotherapy is contraindicated). 4
Post-Traumatic Stress Disorder (PTSD)
PTSD is classified as a trauma/stressor-related disorder (not an anxiety disorder) in DSM-5, requiring exposure to actual or threatened death, serious injury, or sexual violence as Criterion A. 5
Four Symptom Clusters Required
PTSD symptoms must be present for more than 1 month and cause clinically significant distress or functional impairment. 5 All four domains must be represented:
1. Intrusive Experiences (≥1 required)
- Recurrent, involuntary, intrusive distressing memories
- Recurrent distressing dreams related to the trauma
- Dissociative reactions (flashbacks)
- Intense psychological distress at exposure to trauma cues
- Marked physiological reactions to trauma reminders 5
2. Avoidance (≥1 required)
- Avoidance of distressing memories, thoughts, or feelings about the trauma
- Avoidance of external reminders (people, places, conversations, activities, objects, situations) 5
3. Negative Alterations in Cognitions and Mood (≥2 required)
- Inability to remember important aspects of the trauma
- Persistent negative beliefs about oneself, others, or the world
- Persistent distorted cognitions about the cause or consequences leading to self-blame
- Persistent negative emotional state
- Markedly diminished interest or participation in activities
- Feelings of detachment or estrangement from others
- Persistent inability to experience positive emotions 5
4. Alterations in Arousal and Reactivity (≥2 required)
- Irritable behavior and angry outbursts
- Reckless or self-destructive behavior
- Hypervigilance
- Exaggerated startle response
- Problems with concentration
- Sleep disturbance 5
Comorbidity Assessment
The vast majority of individuals with PTSD meet criteria for at least one other psychiatric disorder, and a substantial percentage have 3 or more comorbid diagnoses. 6 The most common are:
- Depressive disorders (most frequent comorbidity across studies) 6, 7
- Substance use disorders (often develop as self-medication attempts) 6
- Other anxiety disorders, particularly GAD 6, 7
The affective symptoms of depression correlate most strongly with emotional numbing in PTSD, while somatic depression symptoms correlate with PTSD hyperarousal. 7 GAD symptoms correlate most strongly with PTSD hyperarousal. 7
Differential Diagnosis from Depression and GAD
Clinicians can reliably distinguish PTSD from major depression and GAD based on: 8
- PTSD-specific features: Trauma exposure requirement, intrusive re-experiencing phenomena (flashbacks, nightmares), trauma-specific avoidance behaviors
- Temporal relationship: Symptoms develop after identifiable traumatic event
- Unique symptom patterns: Hypervigilance and exaggerated startle response are more specific to PTSD than GAD 8
However, recognize substantial symptom overlap exists, particularly with negative affective symptoms, which can lead to underdiagnosis of PTSD when trauma histories are not specifically obtained. 6, 8
Critical Clinical Pitfalls
- Always obtain a detailed trauma history - PTSD is frequently underdiagnosed when clinicians fail to ask about traumatic exposures 6
- Assess for sleep disruption including sleep apnea, nightmares, and insomnia, as treating these may improve PTSD symptoms 5
- Document substance use patterns, as withdrawal states exaggerate PTSD symptoms 6
- Previous depressive disorder is a risk factor for developing PTSD after trauma exposure 6