Psychiatry at a Glance: Disorders Side by Side

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Psychiatry at a Glance

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Place any psychiatric vignette in seconds: 33 comparison tables covering the psychotic, mood, anxiety, trauma, somatic, personality, eating, dissociative, childhood, cognitive, substance, and emergency disorders, sorted by the feature that actually separates them.

Key takeaways

Four questions that place almost any vignette

Is there psychosis

if yes, ask whether it stands alone or only appears during mood episodes. Psychosis alone for more than 2 weeks makes it a psychotic disorder, not a mood disorder.

Is there a mood episode, and which pole

mania and hypomania move the patient into the bipolar spectrum no matter how much depression is in the history.

How long has it lasted

most "which diagnosis" questions in psychiatry are duration questions in disguise, so the duration chart below answers them directly.

Does the patient mind

ego-dystonic (distressed by the symptom) separates OCD from OCPD and avoidant from schizoid personality disorder.

Could a drug or a medical illness explain it

anxiety with hyperthyroidism, depression on propranolol, psychosis on stimulants, and confusion from a urinary tract infection are all answered by treating the cause.

The master duration chart

diagnostic duration, the single highest-yield table in psychiatry
Category	Disorder	Diagnostic duration
Psychotic	Brief psychotic	Under 1 month
	Schizophreniform	1 to 6 months
	Schizophrenia	More than 6 months
	Delusional	More than 1 month
	Schizoaffective	Over 2 weeks of psychosis without mood symptoms
Mood	Major depressive episode	2 weeks or more
	Manic episode	1 week or more
	Hypomanic episode	4 days or more
	Persistent depressive (dysthymia)	2 years or more
	Cyclothymic	2 years or more
Anxiety and trauma	Panic disorder	1 month or more of worry after an attack
	Acute stress	3 days to 1 month
	PTSD	More than 1 month
	Adjustment	Under 6 months after the stressor ends
	Phobias	6 months or more
	GAD	6 months or more
Childhood	Selective mutism	1 month or more
	Separation anxiety	4 weeks or more
	Oppositional defiant	6 months or more
	Specific learning disorder	6 months or more
	Tic disorder (Tourette)	More than 1 year
Sleep and elimination	Narcolepsy	3 months or more
	Enuresis	3 months or more, at least twice weekly
	Encopresis	3 months or more, at least monthly

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Diagnostic Criteria by Symptom Duration

Psychotic disorders

the psychotic spectrum, sorted by duration
Disorder	Duration	Defining detail
Brief psychotic disorder	1 day to 1 month	1 or more positive symptoms, usually stress-related
Schizophreniform disorder	1 to 6 months	2 or more symptoms
Schizophrenia	More than 6 months	At least 1 month of active symptoms; needs 2 or more symptoms including one of delusions, hallucinations, or disorganized speech
Delusional disorder	More than 1 month	One fixed, non-bizarre delusion; functioning otherwise intact
Schizoaffective disorder	Psychosis alone for more than 2 weeks	Mood episodes sit on top of a psychotic baseline
Schizotypal personality disorder	Lifelong pattern	Magical thinking and brief, milder psychotic episodes that never meet criteria

where psychosis sits relative to mood
Diagnosis	Relationship of psychosis to mood episodes
Major depressive episode with psychotic features	Psychosis occurs only with mood episodes; depression is the baseline
Bipolar I	Requires 1 or more manic episodes; psychosis possible during mania or depression
Bipolar II	Hypomania plus a major depressive episode; psychosis possible in depression but never with hypomania
Schizoaffective disorder	Psychosis must also occur alone for more than 2 weeks, so psychosis is the baseline
Schizophrenia	Psychosis without a mood disorder driving it

the two "suspicious patient" diagnoses
Feature	Delusional disorder	Paranoid personality disorder
Content	One specific false belief	No specific delusion, broad general suspicion
Scope of life affected	Narrow, for example only work	Many areas, relationships and work
Example	"My coworkers are stealing from me," everything else normal	Pervasive distrust, hypervigilance, cynical worldview

Full pages

Schizophrenia Spectrum Disorders and Psychosis: Delusions, Hallucinations & Disorganized Thought

Mood episodes: the three building blocks

the episodes every mood diagnosis is built from
Episode	Threshold	Duration	Function	Psychosis
Major depressive	5 or more of 9 "SIG E CAPS", must include depressed mood or anhedonia (irritability in children)	2 weeks or more	Impaired	Possible, mood congruent
Manic	3 or more of "DIG FAST"	1 week or more, or any duration if hospitalized	Marked impairment	Possible
Hypomanic	Same symptoms as mania	4 days or more	No marked impairment, keeps the job	NEVER

bipolar I vs bipolar II vs cyclothymia
Feature	Bipolar I	Bipolar II	Cyclothymic disorder
Required	1 or more manic episodes	1 or more hypomanic plus 1 or more depressive episodes	Fluctuating mild depressive and hypomanic symptoms
History of mania?	Yes	Never	Never
Duration	Not defining	Not defining	2 years or more, symptomatic at least half the time
Practical tell	Hospitalization, job loss, spending sprees	Keeps the job, never hospitalized	Never reaches threshold for either pole
Treatment	Lithium or valproate, plus atypical antipsychotics, lamotrigine, carbamazepine	Same	Same principles

the two chronic milder forms
Feature	Persistent depressive disorder (dysthymia)	Cyclothymic disorder
Mood	Depressive only, 2 or more symptoms	Oscillates between dysthymia and hypomania
Duration	2 years or more (1 year in children)	2 years or more
Remission	Under 2 months	Under 2 months

Full pages

Mood Disorders: Overview and Bipolar Disorder & Cyclothymia

Depression: subtypes and look-alikes

the MDD subtypes
Subtype	Defining features	Treatment
MDD with psychotic features	Hallucinations or delusions, mood congruent (guilt, nihilism, death), only during the episode	Antidepressant plus an atypical antipsychotic, or ECT
MDD with seasonal pattern	Episodes only in one season, usually winter, for 2 or more consecutive years	Standard therapy plus light therapy
Depression with atypical features	Mood reactivity, hypersomnia, hyperphagia, leaden paralysis, rejection sensitivity. The most common subtype	CBT and SSRIs; MAOIs effective but not first line
Persistent depressive disorder	Milder, 2 or more symptoms for 2 years or more	CBT and SSRIs

atypical depression vs ordinary MDD vs pseudodementia
Feature	Atypical depression	Ordinary MDD	Pseudodementia
Mood reactivity	Rapidly reversible with positive events	Persistently low regardless of circumstance	Depressed
Sleep and appetite	Hypersomnia plus hyperphagia	Insomnia, often terminal, with weight loss	Variable
Cognition	Intact	Intact	Apparent decline that is not dementia
Clock-face test	Normal	Normal	Cannot draw it, but finishes quickly when prompted
Treatment	SSRIs; MAOIs notably effective	SSRIs, CBT	Treat the depression

normal grief vs prolonged grief vs major depression
Feature	Normal grief	Prolonged grief disorder	Major depressive disorder
Duration	Adapts within about 6 months	6 to 12 months or longer	2 weeks or more of criteria
Course	Improves in waves	Does not abate with time	Persistently low
Function	Self-care maintained	Neglect of self-care	Socio-occupational impairment
Hallucinations	Of the deceased, never guilt-inducing	Voices saying the patient is worthless	Mood-congruent if psychotic
Is it a disorder?	No	Yes	Yes

Full pages

Major Depressive Disorder and Grief & Prolonged Grief Disorder

Peripartum mood states

the three postpartum presentations
Feature	Postpartum blues	Peripartum depression	Postpartum psychosis
Incidence	50 to 85%	10 to 15%	0.1 to 0.2%
Onset	2 to 3 days after delivery	During pregnancy or within 4 weeks after	First few weeks postpartum
Duration	Resolves within 2 weeks; beyond 10 days think depression	Meets MDD criteria	Until treated
Features	Tearfulness, fatigue, low mood	Persistent sadness, worthlessness or guilt	Delusions, hallucinations, thoughts of harming the baby
Treatment	Supportive, with follow-up	CBT and SSRIs	Hospitalization plus an atypical antipsychotic; ECT if insufficient

Full page

Peripartum Mood Disturbances

Anxiety disorders

anxiety sorted by what the worry attaches to
Disorder	What the worry attaches to	Duration	First line
GAD	Many things or nothing specific, "CRIMES" symptoms	6 months or more	CBT and SSRIs; buspirone second line
Panic disorder	The attacks themselves, peaking in about 10 minutes with 4 or more symptoms	1 month or more of worry after an attack	CBT and SSRIs; benzodiazepine acutely
Adjustment disorder	One identifiable stressor	Within 3 months, resolving under 6 months after it ends	CBT
Specific phobia	One object or situation	6 months or more	Benzodiazepine for acute relief; CBT long term
Social anxiety disorder	Embarrassment in social or performance settings	6 months or more	Beta-blocker for performance type, benzodiazepine if asthmatic; CBT and SSRIs long term
Agoraphobia	2 or more situations where escape is difficult	6 months or more	CBT and SSRIs

Full page

Anxiety Disorders: Panic Disorder, GAD & Phobias

Obsessive-compulsive and trauma-related

OCD vs OCPD, the one-word difference
Feature	OCD	OCPD
Insight	EGO-DYSTONIC, distressed by it	EGO-SYNTONIC, sees nothing wrong
Content	Obsessions, compulsions, or both	Preoccupation with order, perfectionism, control
Treatment	CBT plus SSRIs; clomipramine second line	Psychotherapy

trauma and stress disorders by the clock
Disorder	Time from the event	Treatment
Acute stress disorder	3 days to 1 month	CBT; drugs usually not indicated
PTSD ("HARD")	More than 1 month	CBT, SSRIs, venlafaxine; prazosin for nightmares
Adjustment disorder	Within 3 months of the stressor, resolving under 6 months after it ends	CBT

Full pages

Obsessive-Compulsive & Related Disorders and Trauma & Stress-Related Disorders

Symptoms that are produced, feigned, or unconscious

the 2 by 2 that settles every one of these vignettes
	Malingering	Factitious disorder	Somatic symptom disorders
Symptoms	Intentional	Intentional	Unconscious
Motivation	Intentional	Unconscious	Unconscious
Gain	External: money, drugs, avoiding work or prison	Internal: the sick role, attention	None sought
Invasive procedures	Refuses	Willingly undergoes	Not characteristic
Course	Stops when the gain is obtained	Chronic, recurrent admissions	Chronic and distressing
Management	No treatment indicated	Address the underlying need	Regular visits with one physician

inside the somatic family
Disorder	Defining feature
Somatic symptom disorder	One or more bodily complaints for months to years with excessive anxiety about them
Conversion disorder	Loss of sensory or motor function after a stressor; may show la belle indifference
Illness anxiety disorder	Preoccupation with having a serious illness, with minimal somatic symptoms

Full page

Malingering, Factitious & Somatic Symptom Disorders

Personality disorders

Cluster A, the weird
Disorder	Core feature	Classic vignette
Paranoid	Pervasive distrust and hypervigilance	Projection; impairs many areas of life
Schizoid	Prefers solitude, limited emotional expression	A solitary job with no social contact; ego-syntonic
Schizotypal	Odd beliefs and magical thinking, eccentric appearance	Fixation on astrology; never meets psychosis criteria

Cluster B, the wild
Disorder	Core feature	Classic vignette
Antisocial	Law-breaking with no remorse; must be 18 or older with conduct disorder before 15	Cheated on the bar exam, fired for stealing; the crime need not be violent
Borderline	Unstable mood and relationships, fear of abandonment, self-mutilation; splitting	Parasuicidal cutting, repeated broken engagements. Treatment is DBT
Histrionic	Attention-seeking, dramatic, sexually provocative	Flirtatious with the physician; flamboyant dress
Narcissistic	Grandiosity and entitlement, rage at criticism	Castigates staff over a late appointment

Cluster C, the worried
Disorder	Core feature	Classic vignette
Avoidant	Hypersensitive to rejection but wants relationships	Ego-dystonic: desires contact, cannot engage
Dependent	Excessive need to be cared for, clingy, submissive	Stays in abusive relationships to avoid being alone
Obsessive-compulsive (OCPD)	Order, perfectionism, control	Ego-syntonic; rereads every letter nine times

the three pairs the exam sets against each other
Pair	The discriminator
Schizoid vs avoidant	Schizoid prefers solitude (ego-syntonic); avoidant wants company but fears rejection (ego-dystonic)
Schizotypal vs schizophrenia	Schizotypal has magical thinking and brief milder episodes, never meeting psychotic criteria
Paranoid PD vs delusional disorder	Paranoid PD is general distrust across many areas; delusional disorder is one belief in one area

Full page

Personality Disorders

Eating disorders

anorexia vs bulimia vs binge-eating disorder
Feature	Anorexia nervosa	Bulimia nervosa	Binge-eating disorder
BMI	Below 18.5, and required	Normal or slightly overweight	Often increased
Binges	Only in the binge-purge subtype	Required, weekly for 3 months	Required, weekly for 3 months
Purging	Possible in the binge-purge subtype	Required	Absent, which is the whole distinction
Physical signs	Lanugo, bradycardia, hypothermia, osteoporosis, amenorrhea	Parotid hypertrophy, enamel erosion, Russell sign, Mallory-Weiss tears	Not characteristic
Electrolytes	Hypokalemia if purging	Hypokalemic, hypochloremic metabolic alkalosis	Not characteristic
Treatment	Nutritional rehabilitation, psychotherapy, olanzapine	Psychotherapy, fluoxetine; bupropion contraindicated	Psychotherapy; SSRIs; lisdexamfetamine

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Eating Disorders

Dissociative disorders

the three dissociative diagnoses
Disorder	Core feature	Key association
Depersonalization / derealization	Detachment from one's own body or from the environment	Reality testing intact, which separates it from psychosis
Dissociative amnesia	Cannot recall personal information after severe trauma	May include a fugue, an abrupt unexplained journey away from home
Dissociative identity disorder	2 or more distinct identities	Associated with sexual abuse, PTSD, borderline personality disorder; patients report time loss

Full page

Dissociative Disorders

Childhood and neurodevelopmental disorders

the three early-onset diagnoses students confuse
Disorder	Onset	Core features
ADHD	Before age 12, diagnosed after 4	Hyperactivity, impulsivity, or inattention in 2 or more settings, with normal intelligence
Autism spectrum disorder	Usually before age 3	Social and communication deficits, repetitive behavior, restricted interests; increased head size
Tourette syndrome	Before 18	Motor and vocal tics for more than 1 year; coprolalia not required; linked to OCD and ADHD

defiance vs criminality, across the lifespan
Feature	Oppositional defiant disorder	Conduct disorder	Antisocial personality disorder
Core behavior	Angry, argumentative, defiant toward authority	Violates the rights of others	Disregard for rights, no remorse
Law-breaking	No	Yes	Yes
Age	6 months or more of the pattern	Before 18	18 or older plus conduct disorder before 15

two disorders of explosive anger
Feature	Disruptive mood dysregulation disorder	Intermittent explosive disorder
Age	Onset before 10, diagnosed after 6	Onset after 6
Between outbursts	Constantly angry and irritable	Normal mood
Outburst	Sustained irritability	Under 30 minutes, then remorse

intellectual disability vs specific learning disorder
Feature	Intellectual disability	Specific learning disorder
Deficit	Global	One subject (math, reading, writing)
General intelligence	Impaired	Normal
Causes	Most common overall fetal alcohol syndrome; most common genetic Down syndrome; most common inherited fragile X	Not applicable

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Childhood & Early-Onset Disorders

Confusion: delirium, dementia, and the mimics

delirium vs dementia
Feature	Delirium	Dementia
Onset	Acute, hours to days	Insidious, months to years
Course	Waxing and waning	Steadily progressive
Attention	Impaired, the defining feature	Preserved until late
Hallucinations	Common, often visual	Less common, except Lewy body
EEG	Diffuse slowing	Usually normal
Reversible?	Yes	Generally no

dementia vs pseudodementia vs benign senility
Feature	True dementia	Pseudodementia	Benign senility
Who raises the concern	A family member	Either	The patient, who is worried
Mental status testing	Low score, and the patient tries	Low score from apathy	Essentially normal
Clock-face test	Cannot complete it	Completes it quickly when prompted	Normal
Treatment	Cholinesterase inhibitor	Treat the depression	Reassurance

Full pages

delirium and Orientation & Amnesias

Substances at a glance

intoxication and withdrawal signatures
Substance	Intoxication	Withdrawal
Alcohol	Disinhibition, ataxia, slurred speech	Tremor, seizures, delirium tremens; can be fatal
Benzodiazepines	Ataxia, minor respiratory depression; reverse with flumazenil	Seizures, anxiety, insomnia
Barbiturates	Marked respiratory depression; no antidote	Delirium, cardiovascular collapse
Opioids	Miosis, respiratory depression, constipation; reverse with naloxone	Mydriasis, diarrhea, piloerection, lacrimation; not lethal
Cocaine	Mydriasis, chest pain, perforated nasal septum, formication	Restlessness, hunger, severe depression
Amphetamine	Skin excoriations, prolonged wakefulness, paranoia	Crash with lethargy and vivid nightmares
PCP	Violence, nystagmus, analgesia	Not characteristic
LSD	Visual distortions, synesthesia, flashbacks	Not characteristic
Cannabis	Conjunctival injection, increased appetite, slowed time	Irritability, insomnia, reduced appetite
Nicotine	Restlessness	Irritability, increased appetite and weight

the alcohol withdrawal timeline, in hours from the last drink
Time	Syndrome	Features
6 to 24 h	Tremors and minor withdrawal	Tremor, insomnia, diaphoresis, agitation
12 to 48 h	Alcoholic hallucinosis	Usually visual, with intact reality testing
12 to 48 h	Withdrawal seizures	Generalized tonic-clonic
48 to 96 h	Delirium tremens	Altered mental status, autonomic hyperactivity. Can be fatal

Full pages

Depressant Intoxication & Withdrawal, Opioid Intoxication & Withdrawal, and Stimulant & Hallucinogen Intoxication & Withdrawal

Psychiatric emergencies

the four hyperthermic syndromes
Feature	Serotonin syndrome	Neuroleptic malignant syndrome	Malignant hyperthermia	Anticholinergic toxicity
Trigger	Serotonergic drugs	Antipsychotic (D2 blockade)	Succinylcholine or inhaled anesthetics	Anticholinergics, first-generation H1 blockers, TCAs
Neuromuscular	Clonus and HYPERreflexia	Lead-pipe rigidity, normal reflexes	Rigidity	Normal
Onset	Hours	Days to weeks	Minutes, intraoperatively	Hours
Skin	Diaphoresis	Diaphoresis	Mottled	Hot, red, DRY
Other	Diarrhea	Raised creatine kinase	Raised creatine kinase, hypercapnia	Urinary retention, mydriasis
Antidote	Cyproheptadine	Dantrolene, bromocriptine	Dantrolene	Physostigmine

rigidity with and without fever
Presentation	Diagnosis	Treatment
Rigidity WITHOUT fever, hours to days after an antipsychotic	Acute dystonia	Benztropine or diphenhydramine
Rigidity WITH fever, autonomic instability, raised creatine kinase	Neuroleptic malignant syndrome	Dantrolene, bromocriptine
Clonus and hyperreflexia with fever and diarrhea	Serotonin syndrome	Cyproheptadine

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Psychiatric Emergencies

First-line treatment in one line each

what to give, by diagnosis
Diagnosis	First line	Notable alternative or caution
Major depressive disorder	CBT and an SSRI	SNRI, mirtazapine, bupropion; ECT or ketamine if severe or refractory
MDD with psychotic features	Antidepressant plus an atypical antipsychotic	ECT
Bipolar disorder	Lithium or valproate	Atypical antipsychotic, lamotrigine; antidepressants alone can trigger mania
Schizophrenia	Atypical antipsychotic (risperidone)	Haloperidol decanoate if adherence is poor
Panic disorder	SSRI plus CBT	Benzodiazepine for the acute attack
GAD	CBT and an SSRI	Buspirone; benzodiazepines second line
Social anxiety (performance type)	Beta-blocker	Benzodiazepine if asthmatic
OCD	CBT plus an SSRI	Clomipramine
PTSD	CBT, SSRI, or venlafaxine	Prazosin for nightmares
Acute stress and adjustment disorder	CBT	Medication usually not indicated
Borderline personality disorder	Dialectical behavioral therapy	Treat comorbid mood or substance disorder
Anorexia nervosa	Nutritional rehabilitation and psychotherapy, olanzapine	Mirtazapine if depressed; admit if BMI under 15
Bulimia nervosa	Psychotherapy plus fluoxetine	Bupropion contraindicated
Binge-eating disorder	Psychotherapy	SSRI, lisdexamfetamine
Postpartum psychosis	Hospitalization plus an atypical antipsychotic	ECT if insufficient
Delirium	Treat the underlying cause	Antipsychotic only for dangerous agitation
Alcohol withdrawal	Benzodiazepine	Thiamine before glucose
Opioid overdose	Naloxone	Methadone or buprenorphine for withdrawal and maintenance

How it's tested

Most "which diagnosis" items are decided by one variable: duration, whether psychosis stands alone, whether the patient is distressed by the symptom, or whether a drug explains it. Read the four questions at the top, then jump to the table that owns that variable.

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Psychiatry at a Glance: Disorders Side by Side

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