Positive symptoms, SIG E CAPS, and the duration criteria that define the spectrum
A 22-year-old man has 4 months of auditory hallucinations, paranoid delusions, disorganized speech, and withdrawal from friends. No medical cause has been identified. His psychosis has been present continuously for 4 months. Which is the MOST accurate diagnosis?
Same symptom clusters, different duration cutoffs. Duration is the entire boards question.
| Diagnosis | Duration | Key Feature | Prognosis |
|---|---|---|---|
| Brief Psychotic | < 1 month | Often stressor-triggered. Sudden onset. | Good. Full return to baseline. |
| Schizophreniform | 1 to 6 months | Same criteria as schizophrenia, shorter duration. May resolve. | Variable. 1/3 recover fully. |
| Schizophrenia | ≥ 6 months | 2 of 5 active-phase symptoms for 1 month, total 6+ months disturbance. | Chronic. Lifelong management. |
| Schizoaffective | Same as schizophrenia | Psychosis + major mood episode (depressive or manic) concurrent. Psychosis must also exist 2+ weeks WITHOUT mood episode. | Better than schizophrenia, worse than pure mood disorder. |
| Delusional Disorder | > 1 month | Non-bizarre delusions only. No hallucinations. Functioning largely intact. | Chronic but often functional. |
DSM Criteria · Active Phase
Requires 2 of 5 active-phase symptoms for at least 1 month (or less if treated): delusions, hallucinations, disorganized speech, disorganized or catatonic behavior, negative symptoms. Total duration of disturbance (including prodrome/residual) must be 6+ months.
Epidemiology: lifetime risk 1%. Men onset early 20s, women late 20s. Viral exposure in utero (influenza), winter birth, and urban upbringing increase risk.
Dopamine hypothesis: excess D2 activity in mesolimbic pathway = positive symptoms. D1 deficiency in prefrontal cortex = negative and cognitive symptoms. Antipsychotics block D2 to treat positive symptoms. Negative symptoms are harder to treat.
Glutamate hypothesis: NMDA receptor hypofunction underlies negative and cognitive symptoms. Ketamine and PCP block NMDA and produce a schizophrenia-like state with both positive and negative features.
Duration < 1 month
Full psychotic episode, then complete return to premorbid functioning. Often triggered by an identifiable stressor. Good prognosis. The stressor-triggered subtype is sometimes called brief reactive psychosis.
Duration 1 to 6 months
Identical criteria to schizophrenia, just not enough time has passed yet. About one-third resolve and never convert. Two-thirds go on to meet schizophrenia criteria. Good prognostic features: acute onset, confusion during episode, no flat affect.
Psychosis + Mood
Psychosis must overlap with a major mood episode (manic, mixed, or depressive). The critical distinguisher from "Bipolar I with psychotic features": psychosis must persist for 2 or more weeks WITHOUT a mood episode. Two subtypes: bipolar type (mania or mixed) and depressive type.
Non-bizarre Delusions Only
Fixed, non-bizarre delusions (i.e., could theoretically happen: being followed, spouse infidelity, having a disease). No hallucinations. No significant functional impairment. Functioning is preserved. Duration more than 1 month. Folie a deux (shared psychotic disorder): person adopts delusions of a dominant close contact.
Positive Symptom 1
Perception without external stimulus. Hierarchy by boards frequency: auditory > visual > tactile > olfactory. Auditory is the most common type and the most board-tested.
Command hallucinations (voices telling patient to harm self or others) = highest safety risk. Always assess for command hallucinations when a psychotic patient expresses SI/HI.
Positive Symptom 2
Fixed false beliefs not amenable to reason. Types by frequency: persecutory #1 (being followed, poisoned), grandiose (#2), erotomanic (famous person loves them), somatic (disease conviction), referential (events/media are directed at them personally).
Bizarre delusions (impossible, like thought insertion) are sufficient alone to count as one criterion.
Positive Symptom 3
Reflects a breakdown in the normal flow of thought. Patterns: loose associations (tangential topic jumps), tangential replies (answers that leave the question entirely), word salad (incoherent jumble), neologisms (invented words), clang associations (rhyming-driven speech, e.g., "I like Mike who is a spike on a bike").
Positive Symptom 4 + 5
Disorganized behavior: unpredictable, goal-less actions. Inappropriate affect (laughing at funerals). Inability to perform activities of daily living.
Catatonia: motor dysregulation spectrum. Waxy flexibility (limb stays in position placed), posturing, stupor (unresponsive), or excited catatonia (purposeless agitation). Catatonia can also occur in severe mood disorders.
The 5 A's
Affect (flat/blunted): reduced or absent emotional expressiveness. Flat face, monotone voice.
Alogia: poverty of speech. Short, empty answers. Not picking up conversation threads.
Avolition: lack of motivation to initiate and sustain goal-directed activities. The patient just sits.
Anhedonia: inability to experience pleasure. Previously enjoyable activities no longer interest them.
Associality: social withdrawal, reduced desire for relationships. Not the same as social anxiety.
Cognitive Domain
Impaired working memory (holding information briefly in mind), executive function (planning, task-switching, inhibition), and sustained attention. These are the strongest predictors of vocational and social functioning in schizophrenia.
Cognitive symptoms often predate the first psychotic break (prodromal period). They are largely unresponsive to current antipsychotic medications.
SIG E CAPS for depression. DIGFAST for mania. Duration and polarity tell the rest.
Diagnosis · SIG E CAPS
Criteria: 5 or more of 9 symptoms for at least 2 weeks. Must include depressed mood OR anhedonia (these are the "anchors"). Symptoms represent a change from baseline. Cause significant distress or impairment. Not attributable to substance or medical condition.
Specifiers that change management:
Melancholic: severe, worse in AM, psychomotor changes (retardation or agitation), inability to feel better even briefly (no reactivity), early morning awakening, excessive guilt. Best response to TCAs and ECT.
Atypical: mood brightens with positive events (reactive), hypersomnia, hyperphagia, leaden paralysis, rejection sensitivity. Best response to MAOIs (board favorite).
Psychotic: delusions or hallucinations. Add antipsychotic. ECT is first-line for severe cases.
Peripartum: during pregnancy or within 4 weeks of delivery (up to 1 year per some criteria).
Treatment: SSRI first-line for most. CBT equally effective for mild to moderate. ECT for severe, refractory, or immediate SI.
Full Mania Required
Requires at least 1 manic episode. Manic episode criteria: elevated, expansive, or irritable mood plus increased goal-directed activity or energy, lasting 7 or more days (or any duration if hospitalized or psychotic features present). 3 of 7 DIGFAST symptoms (4 if only irritable).
A depressive episode is common but NOT required for Bipolar I. Many patients remember their manias fondly and resist treatment.
Hypomania + Depression Required
Requires at least 1 hypomanic episode AND 1 major depressive episode. Hypomania: same DIGFAST criteria but lasts only 4 or more days, is NOT severe enough to require hospitalization, and has NO psychotic features. Functioning may actually improve during hypomania. Patient has never had a full manic episode. Converting to mania reclassifies to Bipolar I.
Cyclothymia
At least 2 years of numerous periods with hypomanic symptoms AND depressive symptoms that do NOT meet full criteria for a hypomanic or major depressive episode. Never symptom-free for more than 2 months. Significantly milder than Bipolar II. Treatment: mood stabilizers (often lithium or lamotrigine).
Bipolar Treatment Highlights
Lithium: first-line for Bipolar I (acute and maintenance), strongest evidence for suicide prevention. Monitor: thyroid, renal, and serum levels. Narrow therapeutic index. Toxicity: tremor, polyuria, GI upset. Severe toxicity: cardiac arrhythmia, seizure.
Valproate: good for rapid cycling and mixed episodes. Teratogenic (neural tube defects). Monitor LFTs, CBC.
Lamotrigine: best for bipolar depression. Risk of Stevens-Johnson syndrome if titrated too fast.
Depressed Mood ≥ 2 Years
Formerly "dysthymia." Depressed mood most of the day, more days than not, for at least 2 years (1 year in children). Does not meet full MDD criteria. At least 2 of: poor appetite or overeating, insomnia or hypersomnia, low energy, low self-esteem, poor concentration, hopelessness. Never more than 2 months symptom-free. Patients often say they have "always been this way."
Luteal Phase
Severe mood symptoms (irritability, depression, anxiety, affective lability) in the luteal phase of the menstrual cycle, resolving within a few days of menses onset. Must be documented over 2 cycles. Significantly impairs functioning. Treatment: SSRIs (luteal phase or continuous) are first-line; OCPs are second-line.
Identifiable Stressor
Emotional or behavioral symptoms within 3 months of an identifiable stressor. Symptoms are disproportionate to the stressor's magnitude. Do not meet criteria for another mental disorder. Resolves within 6 months after the stressor ends. Can be with depressed mood, anxious mood, mixed mood, disturbance of conduct, or mixed disturbance. Treatment: supportive therapy, short-term counseling.
Grief vs MDD
Normal grief after bereavement: sadness comes in waves, often triggered by reminders of the deceased. The person still experiences positive emotions. Thoughts are focused on the deceased (not generalized hopelessness). Preserved self-esteem. No anhedonia for other aspects of life.
When to diagnose MDD: if symptoms are pervasive, persistent, include hopelessness, worthlessness, and anhedonia for all activities, across all contexts, for 2 or more weeks, MDD can be diagnosed even concurrent with bereavement.
SAD PERSONS, direct assessment, and the one medication with the strongest evidence.
S · Sex: males complete more. Females attempt more.
A · Age: bimodal risk. Adolescents (15 to 24) and elderly (75+) have highest rates.
D · Depression: strongest psychiatric risk factor. MDD, bipolar, schizoaffective all elevate risk.
P · Previous attempt: single strongest predictor of future completion. Past attempt 30 to 40x higher risk than general population.
E · Ethanol and substance use: disinhibits, impairs problem-solving, elevates impulsivity.
R · Rational thinking loss: psychosis, particularly command hallucinations, dramatically increases risk.
S · Social support lacking: isolation, recent divorce/separation, no close relationships.
O · Organized plan: a specific plan with method, time, place = high risk.
N · No spouse (widowed, separated, divorced).
S · Sickness: chronic medical illness, especially terminal diagnosis, intractable pain.
Asking about suicide does NOT increase suicidal behavior. Ask directly: "Are you having thoughts of hurting or killing yourself?"
Ladder of risk:
1. Passive ideation: "I wish I were dead" (not a plan, but still serious)
2. Active ideation without plan: wants to die, no specific method
3. Active ideation with plan: "I will use my gun at home"
4. Active ideation with intent: intends to carry out the plan
5. Access to means: has the firearm, the pills, the location
Columbia Suicide Severity Rating Scale (C-SSRS): validated tool used in clinical settings.
Hospitalize when: active plan + intent, or access to lethal means, or command hallucinations with intent, or patient cannot contract for safety.
Means restriction: most effective single intervention. Removing firearms from the home reduces suicide risk substantially. Ask every at-risk patient about firearms and involve family in securing them.
Lithium: the strongest pharmacological evidence for suicide prevention. Reduces completed suicide 6 to 7 times in bipolar disorder. Consider for any high-risk bipolar patient.
Clozapine: the only antipsychotic with FDA approval for reducing suicidal behavior in schizophrenia and schizoaffective disorder. First-line for high-risk schizophrenia patients. Requires weekly CBC monitoring (agranulocytosis risk).
Follow-up within 1 week of discharge: highest-risk period for reattempt is the 3 months post-discharge, especially the first 7 days.
One clue at a time. Eliminate wrong diagnoses until one is standing.
Four board-style questions. Original vignettes. Pick your answer before the explanation.
A psychiatry attending teaches that MDD requires 5 of 9 SIG E CAPS criteria for at least 2 weeks. A student asks whether any of the 9 symptoms are required, or whether any combination of 5 suffices.
Which of the following MUST be present as one of the five symptoms to diagnose a major depressive episode?A 28-year-old woman is referred by her primary care physician after her husband noticed she spent $15,000 on furniture in one weekend, slept only 2 hours per night for 5 days, and was "talking a mile a minute." She was admitted involuntarily for 3 days. She has also had two prior episodes of major depression. She denies any previous episodes like this.
What is the key feature that distinguishes this patient's diagnosis from Bipolar II disorder?A 34-year-old man with schizophrenia is brought to the emergency department by police after neighbors reported him standing in the street shouting that "the voices are telling me to get a knife and go to my neighbor's house." He is agitated and appears frightened.
What is the FIRST clinical priority in this patient's assessment?A 45-year-old man presents to his physician for a check-up. His wife of 18 years died 4 months ago from cancer. He reports feeling profoundly sad and missing her every day. He occasionally thinks he sees her face in a crowd and then realizes it is a stranger. He has lost 6 pounds because he "just forgets to eat sometimes." He has no suicidal ideation. He is back at work part-time and still meets with friends occasionally. He says, "Some days are better than others."
Which diagnosis BEST fits this presentation?Original board-style vignettes. Shuffled, never-repeat, full explanations for every choice.