Low Mood Algorithm

Safety

Red Flags — Suicide Risk, Psychosis, Mania and Safeguarding First

Done

Ask about suicidal thoughts directly at the first contact — asking does not increase risk. A positive answer needs a clinical conversation, not a score.

Overdose taken, serious self-injury or attempt in progress Any ingestion with intent, or injury needing treatment → 999 Emergency department; do not wait for symptoms after an overdose

Suicidal intent, a plan, or unable to stay safe Active plan, preparation, access to means, recent attempt, hopelessness, intoxication → Same-day Local mental-health crisis team (NHS 111 option 2 out of hours); 999 if immediate danger to life

Psychotic symptoms Delusions of guilt, poverty or illness, hallucinations, severe agitation or stupor → Same-day Crisis or community mental-health assessment

Possible mania or hypomania Elevated or irritable mood, reduced need for sleep, pressured speech, grandiosity, risky behaviour → Same-day Mental-health assessment if acutely manic, psychotic or at risk; do not start an antidepressant alone

Perinatal warning signs Rapidly changing mental state, new thoughts or acts of violent self-harm, new feelings of incompetence as a mother or estrangement from the baby → Same-day Specialist perinatal mental-health assessment (NICE CG192); postpartum psychosis → 999 or crisis team

Not eating or drinking, severe self-neglect Marked weight loss, dehydration, stupor, unable to care for self or dependants → Same-day Crisis assessment; consider medical admission

Safeguarding concern Children or dependants at risk, domestic abuse, exploitation, a vulnerable adult being harmed → Same-day Act under local safeguarding procedures; record who else lives at home

Older adult with acute confusion New fluctuating attention, drowsiness or agitation → Same-day Delirium until shown otherwise — find the medical cause

NICE NG225 (2022) advises against using risk assessment tools and scales to predict future suicide or repetition of self-harm, against using them to decide who should or should not be offered treatment, and against global low/medium/high risk stratification. Instead, have a person-centred conversation about the person's thoughts, intent, plan, means, previous self-harm, alcohol and drugs, circumstances and protective factors, and agree a safety plan. PHQ-9 item 9 is a prompt, not a risk assessment.

Most people who die by suicide after self-harm had been judged "low risk" on standard tools — which is why the conversation, not the score, decides the plan.

Diagnose

History — The Mood, the Risk and the Context

Done

Core symptoms

Persistent low mood and/or loss of interest or pleasure (anhedonia) on most days for at least 2 weeks

Associated symptoms

Sleep (early waking, or too much), appetite and weight change, fatigue, poor concentration, worthlessness or guilt, psychomotor change, thoughts of death

Duration and impact

Onset, triggers, course; work, relationships, self-care, caring responsibilities. Number and severity of symptoms decide severity, not the label

Suicide and self-harm

Thoughts of death or suicide, plans, intent, preparation, means at home (stockpiled medicines, firearms), previous self-harm or attempts, hopelessness, protective factors (people, faith, pets, future plans)

Mania screen

Ever had days of feeling high or irritable with little need for sleep, racing thoughts, overspending or risk-taking? Family history of bipolar disorder or suicide

Losses and life events

Bereavement (when, whom, how), relationship breakdown, job loss, debt, housing, caring stress, discrimination, trauma

Perinatal

Pregnant or within a year of birth: mood, anxiety, bonding, thoughts of harm to self or baby, past perinatal illness, partner and family support

Alcohol and drugs

AUDIT-C; cannabis, stimulants, opioids, benzodiazepines; withdrawal states. Alcohol is the commonest modifiable driver of low mood

Medicines

Corticosteroids, isotretinoin, hormonal contraception, levetiracetam and some antiepileptics, interferon, efavirenz, finasteride, montelukast, beta-blockers, opioids, benzodiazepines; recent stopping of an antidepressant

Physical symptoms

Weight loss, cold intolerance, breathlessness, pain, snoring with daytime sleepiness, memory problems, menopausal or premenstrual pattern

PHQ-9

Measure, not diagnosis Records severity and gives a baseline to track response; diagnosis rests on the clinical interview

Screening for past mania before prescribing matters: an antidepressant alone can tip someone with bipolar disorder into mania or a mixed state. Asking who lives at home is both a protective-factor question and a safeguarding question — depression in a parent or carer can affect children and dependants.

Drug-induced mood change is easy to miss because the temporal link is weeks to months. Do not stop an important medicine without weighing risk and benefit.

Diagnose

Examination and Targeted Investigations

Done

Mental state

Appearance and self-care, eye contact, psychomotor slowing or agitation, speech, mood and affect, thought content (guilt, hopelessness, delusions), perceptions, cognition, insight

Physical examination

Weight and BMI, pulse, BP; thyroid signs, pallor, signs of alcohol misuse, neurological signs where the history suggests; injuries or self-harm marks when appropriate

Bloods by indication

TSH FBC + ferritin B12 + folate HbA1c U&E, LFTs, calcium — guided by history, age, medicines and atypical features, not a universal panel

Older adults

Brief cognitive assessment; sodium before an SSRI if at risk of hyponatraemia; consider dementia and delirium; review anticholinergic and sedative load

Other tests

Pregnancy test where relevant; ECG before citalopram or escitalopram with cardiac disease, QT-prolonging drugs or electrolyte disturbance

Not routine

Brain imaging is not needed for depression without neurological signs, new cognitive decline or atypical features

Hypothyroidism, anaemia, B12 deficiency, hypercalcaemia and diabetes can all present as low mood and fatigue. Test when the history points to them, rather than ordering a fixed panel for everyone. A new depression in later life with cognitive change warrants looking for dementia, vascular disease and medication effects.

Diagnose

Differentials — What Kind of Low Mood Is This?

Done

Depression

2+ weeks, most days

Low mood or anhedonia with associated symptoms and impaired function. NICE NG222 grades it as less severe (PHQ-9 under 16) or more severe (16 or over), alongside clinical judgement

Bipolar depression

Past highs

Previous mania or hypomania, early onset, family history, postpartum onset, antidepressant-induced highs. Seek specialist advice before treating

Grief

After a loss

Waves of yearning and sadness linked to reminders, self-esteem preserved. Prolonged grief: intense, disabling grief persisting beyond about 6–12 months

Adjustment disorder

After a stressor

Distress out of proportion to an identifiable stressor, starting soon after it, expected to settle as the person adapts

Perinatal depression

Pregnancy to 1 year

Same features plus worries about the baby and bonding. Distinguish from the "baby blues" (first 2 weeks, mild, self-limiting) and postpartum psychosis (emergency)

Alcohol or substance-related

Drinking, drugs, withdrawal

Mood often lifts within weeks of stopping heavy drinking; treat both together

Organic or drug-induced

Physical cause

Hypothyroidism, anaemia, B12 or folate deficiency, hypercalcaemia, OSA, Parkinson's disease, stroke, cancer, chronic pain; medicines listed in step 2

Dementia or delirium (older people)

Cognitive change

Apathy and withdrawal can mimic depression; depression can mimic dementia. Delirium fluctuates and has a medical cause

Other mental-health conditions

Comorbidity

Anxiety disorders, PTSD, eating disorders, premenstrual dysphoric disorder, menopause-related low mood, personality-related difficulties

Grief and adjustment are normal responses that usually need support rather than medicines; depression can develop on top of either, so reassess if symptoms persist or deepen. Bipolar depression is commonly first diagnosed as unipolar depression — the mania screen is the safeguard.

Diagnose

Formulate — Severity, Risk Plan and Shared Decision

Done

Severity

Less severe (PHQ-9 under 16, fewer symptoms, function largely preserved) or more severe (PHQ-9 16 or over, many symptoms, marked impairment) — NICE NG222

Risk formulation

Summarise in words: thoughts, intent, plan, means, triggers, protective factors, who knows. No low/medium/high label (NICE NG225)

Safety plan

Warning signs, coping steps, people and places, professional and crisis contacts, making the environment safer (reduce access to means)

Choice

Discuss the options for the severity, previous response, preference and practical access — and agree what happens next

Who else is affected

Children or dependants at home, caring responsibilities, a vulnerable adult — consider safeguarding and carer support

NICE NG222 asks for a shared decision on treatment: the least intrusive effective option first for less severe depression, and a combination of psychological therapy and an antidepressant as the most effective option for more severe depression.

Refer

Referral — Who, Where and How Fast

Done

999

Overdose or serious self-injury, immediate danger to life, postpartum psychosis with risk

Same-day

Suicidal intent or plan or unable to stay safe; psychotic depression; acute mania; severe self-neglect; perinatal warning signs (perinatal mental-health team); safeguarding concerns

Urgent

Suspected bipolar disorder without acute risk (specialist assessment); more severe depression not responding, or with complex comorbidity → community mental-health team per local pathway

NHS Talking Therapies

Self-referral (nhs.uk/talking-therapies) or GP referral for guided self-help, CBT, behavioural activation, counselling, interpersonal therapy

Perinatal mental health

Moderate or severe illness in pregnancy or the first year, past severe perinatal illness or bipolar disorder (NICE CG192)

Under 18

CAMHS — see NICE NG134; do not start an antidepressant in primary care

Memory service

Older adults with cognitive impairment once delirium, depression and reversible causes are considered

Other routes

Drug and alcohol services, bereavement support (e.g. Cruse), social prescribing, debt and housing advice

Most low mood is managed in primary care with NHS Talking Therapies. Specialist mental-health input is for risk, psychosis, bipolar disorder, severe or treatment-resistant depression and complex comorbidity.

Treat

Treatment at This Consultation — NICE NG222

Done

Less severe depression

Guided self-help or group therapy First-line

Least intrusive option first: guided self-help, group CBT or behavioural activation via NHS Talking Therapies (self-referral today). Do not routinely offer an antidepressant first-line unless that is the person's preference

More severe depression

Therapy + antidepressant Offer

Combination of individual CBT and an antidepressant is the most effective option; individual CBT or behavioural activation, or an antidepressant alone, are alternatives by preference

Grief or adjustment

Support and review No routine drugs

Normalise, signpost bereavement or practical support, address sleep and alcohol, review in 2–4 weeks; treat depression if it develops

Suspected bipolar

Specialist advice Caution

Do not start an antidepressant alone; seek specialist assessment (urgent, or same-day if risk)

If startingAn SSRI is usually first choice (safety and tolerability). Sertraline — usual adult dose 50 mg once daily, morning or evening, with or without food (SPC); check the SPC and local formulary. Older adults: baseline sodium if at risk; with NSAIDs, anticoagulants or antiplatelets consider gastroprotection

CounselBenefit builds over 2–4 weeks; early nausea, jitteriness or agitation; possible increase in suicidal thoughts early on — contact the same day if this happens; do not stop suddenly; avoid alcohol

Overdose riskPrescribe limited quantities (for example 1–2 weeks) where there is suicide risk; avoid tricyclics; involve family in holding medicines where agreed

PerinatalWeigh the risks of untreated illness against treatment; sertraline has the most data in pregnancy and breastfeeding — discuss with perinatal mental health for moderate or severe illness (NICE CG192)

Cause foundTreat the organic cause; brief alcohol intervention with AUDIT-C; review any culprit medicine with the prescriber

TodaySafety plan and crisis numbers saved in the phone; fit note if needed; Talking Therapies self-referral details; review date booked

Next steps: see Depression · Anxiety disorders · Postnatal depression · Harmful drinking and alcohol dependence · Hypothyroidism · Dementia

NICE NG222 (2022) ranks guided self-help first for less severe depression and advises against routinely offering antidepressants first-line unless the person prefers them; SSRIs are the preferred antidepressant because of safety and tolerability. For more severe depression, combined individual CBT and an antidepressant is the most clinically and cost-effective option. Second-line choices, switching and long-term continuation are in the Depression protocol.

Lifestyle

Self-Care and Support

Done

Activity and routine Regular physical activity and a daily structure — small, planned, pleasurable or useful activities (behavioural activation)

Sleep Fixed wake time, limit daytime napping, caffeine and evening alcohol; see the insomnia pathway if sleep is the main problem

Alcohol and drugs Cutting down often lifts mood within weeks; no more than 14 units a week spread over 3 or more days

Connection Talk to trusted people; peer support, community groups, social prescribing link workers

Practical problems Debt, housing, benefits and work advice; Citizens Advice; occupational health or a phased return

Support lines Samaritans 116 123 (24 hours), Shout text 85258, NHS 111 option 2; Every Mind Matters for self-help

Behavioural activation and exercise both have evidence in depression and give the person something active to do while waiting for therapy. Practical stressors such as debt are strongly linked with depression and suicide risk.

Safety

Follow-Up and Safety-Netting

Done

1 week

After starting an antidepressant if aged 18–25 or at increased risk of suicide (NICE NG222)

2 weeks

After starting an antidepressant for everyone else; then regularly — about every 2–4 weeks for the first 3 months

2–4 weeks

No drug started: review mood, risk, engagement with therapy and test results; repeat PHQ-9 as a measure of change

Safety-net 999

Immediate danger to life, overdose or serious self-injury

Safety-net same-day

Suicidal thoughts getting stronger, a plan, or feeling unable to stay safe → crisis line, NHS 111 option 2 or the surgery today; new agitation or restlessness after starting a tablet; feeling high or not needing sleep; in pregnancy or after birth, any thoughts of harm to self or baby

Continuity

Same clinician where possible; check that Talking Therapies contact happened; follow up missed appointments in people at risk

The early weeks after starting an antidepressant, and after a crisis or discharge, are periods of higher risk. A named follow-up date, a written safety plan and crisis numbers in the person's phone are simple, high-value safety measures.

🌧️ Low Mood

Red Flags — Suicide Risk, Psychosis, Mania and Safeguarding First

History — The Mood, the Risk and the Context

Examination and Targeted Investigations

Differentials — What Kind of Low Mood Is This?

Formulate — Severity, Risk Plan and Shared Decision

Referral — Who, Where and How Fast

Treatment at This Consultation — NICE NG222

Self-Care and Support

Follow-Up and Safety-Netting