Determining Underlying Psychiatric Disorders in Adults: A Structured Evaluation Framework
The initial psychiatric evaluation must systematically assess psychiatric symptoms through a comprehensive review of systems, substance use, medical conditions, and mental status examination, while actively ruling out medical mimics through targeted physical examination and history-taking focused on neurologic, cardiac, and respiratory systems. 1, 2
Core Assessment Components
Psychiatric Symptom Identification
Begin by conducting a psychiatric review of systems that specifically evaluates:
- Anxiety symptoms and panic attacks 1
- Sleep abnormalities including sleep apnea 1
- Impulsivity 1
- Current and past psychiatric diagnoses 1
- Prior psychotic or aggressive ideation (thoughts of physical/sexual aggression or homicide) 1
- Prior aggressive behaviors including homicide, domestic violence, or other physically/sexually aggressive acts 1
- Suicidal ideation, plans, and attempts (including aborted or interrupted attempts, with details of context, method, damage, potential lethality, and intent) 1
- Intentional self-injury without suicidal intent 1
Treatment History Documentation
Document the complete psychiatric treatment history including:
- Psychiatric hospitalizations and emergency department visits 1
- Past psychiatric treatments with type, duration, and doses 1
- Response to past treatments 1
- Adherence patterns to pharmacological and non-pharmacological treatments 1
Substance Use Assessment
Systematically evaluate:
- Tobacco, alcohol, marijuana, cocaine, heroin, and hallucinogen use 1
- Misuse of prescribed or over-the-counter medications and supplements 1
- Current or recent substance use disorders or changes in substance use patterns 1
Medical Mimic Identification
This is a critical step that prevents misdiagnosis—medical conditions can present with psychiatric symptoms in 9.1% of psychiatric presentations. 3
High-Risk Features Requiring Medical Workup
Immediately suspect medical causality when you observe:
- Visual hallucinations (indicates medical etiology until proven otherwise) 3
- Atypical features uncharacteristic of primary psychiatric disorders 4
- Changes in functionality or age of onset that are unusual 4
- Abnormal vital signs 2
- New-onset psychiatric symptoms in patients without prior psychiatric history 4, 3
Targeted Medical History
Obtain specific information about:
- Allergies and drug sensitivities 1
- All current and recent medications (prescribed, non-prescribed, herbal supplements, vitamins) and their side effects 1
- Relationship with primary care provider 1
- Cardiopulmonary status 5
- Endocrinological disease 5
- Infectious diseases (STDs, HIV, tuberculosis, hepatitis C) 5
Physical Examination Requirements
Perform and document:
- Height, weight, and BMI 2
- Vital signs 2
- Skin examination for stigmata of trauma, self-injury, or drug use 2
- Coordination and gait to identify neurological abnormalities 2
- Involuntary movements or abnormalities of motor tone (may indicate medication side effects, neurological disorders, or specific psychiatric conditions) 2
- Sight and hearing (sensory deficits can masquerade as cognitive or psychiatric impairment) 2
A focused medical assessment based on history and physical examination is superior to routine laboratory testing in psychiatric patients with normal vital signs and non-contributory examinations. 2
Mental Status Examination
Systematically document:
- General appearance and nutritional status 2
- Speech fluency and articulation (rate, rhythm, volume, pressured speech, poverty of speech, dysarthria) 2
- Current mood state and anxiety level through both patient report and clinical observation 2
- Hopelessness (critical risk factor for suicide) 2
- Thought content and process (logical flow, coherence, tangentiality, circumstantiality, flight of ideas, thought blocking) 2
- Perception and cognition (orientation, memory, attention, executive function) 2
Risk Assessment Documentation
For suicidal ideation, evaluate and document:
- Current suicidal ideas, plans, and attempts (active or passive thoughts) 2
- Patient's intended course of action if symptoms worsen 2
- Access to suicide methods 2
- Possible motivations for suicide 2
- Reasons for living 2
- Documented estimate of suicide risk with factors influencing that risk 2
For violence risk, evaluate and document:
- Current aggressive or psychotic ideas including thoughts of physical/sexual aggression or homicide 2
- Documented estimate of aggressive behavior risk (including homicide) with factors influencing that risk 2
Common Medical Conditions Presenting as Psychiatric Disorders
The most frequent medical illnesses presenting with psychiatric symptoms are (in order of frequency):
- Infectious diseases 3
- Pulmonary diseases 3
- Thyroid disorders 3
- Diabetic conditions 3
- Hematopoietic disorders 3
- Hepatic diseases 3
- CNS diseases 3
Note that 46% of patients with medical mimics had illnesses previously unknown to them or their physician. 3
Critical Pitfalls to Avoid
Never skip systematic symptom assessment even when patients drive the agenda—patients may be reluctant to reveal emotional problems due to stigma, leading to missed diagnoses. 6
Never assume stable symptoms mean psychosocial assessment is unnecessary—psychosocial factors predict healthcare utilization and relapse independent of symptom severity. 6
Never rely solely on standardized diagnostic interviews without clinical judgment—these instruments cannot make specific differential diagnoses and catch only unspecific syndromes, particularly problematic with somatic comorbidity. 7
Documentation Requirements
Document:
- Rationale for treatment selection with specific factors influencing treatment choice 2
- All assessment sections with date and time 5
- Authentication by the evaluating clinician 5
Clinical judgment is essential in tailoring the psychiatric evaluation to each patient's unique circumstances and determining which questions are most important for initial assessment. 1, 2