3 Clinical psychopharmacology3.4 Therapeutics

3.4.1.2.2 Phases of illness

Creator: Resident Doctor Committee
Published: 2026-10-14T21:05:16.259Z

2 min read1 figure

Written by Resident Doctor Committee · Published 14 October 2026

The three phases

Treatment may control an episode, consolidate remission or prevent recurrence. Name the current phase rather than continuing or stopping by default.

Phase	Runs from	Purpose	Review interval
Acute	Active episode to adequate control	Treat current symptoms and risk	Often days
Continuation (subacute)	Initial response through consolidation	Prevent relapse of the same episode	Often weeks
Maintenance	Sustained recovery	Prevent new episodes	Often months

Relapse is a return before recovery and recurrence is a new episode after it, although the boundary varies.
Functioning often recovers more slowly than symptoms.

Acute phase

Severe depression, mania, catatonia or psychosis may need urgent specialist treatment, including electroconvulsive therapy.

Check observations, substances and interactions before sedating, and tell oversedation apart from improvement.
Prefer oral treatment; any other route needs a clear indication.
Attend to consent, capacity and legal safeguards despite the urgency.
Review early adverse effects and suicide risk without waiting for full efficacy.

Continuation phase

Residual symptoms raise relapse risk, so aim for remission and better functioning. Before adding medication, decide whether a symptom is residual illness or an adverse effect.

Presentation	Residual illness	Adverse effect
Apathy and slowing	Residual depression	Antipsychotic parkinsonism
Blunted emotion	Negative symptom	Selective serotonin reuptake inhibitor effect
Restlessness	Anxiety	Akathisia

Once the acute need passes, review temporary benzodiazepines, hypnotics, antimuscarinics and other crisis additions.
Sedation or sexual dysfunction may become less acceptable after recovery.

Maintenance phase

Repeated, severe or closely spaced episodes favour prevention; full recovery after a single mild episode may favour a shorter course.
Monitor metabolic, renal, endocrine, motor and cognitive harms.
Formulation and dosing frequency affect adherence, and a depot goes on acting after injection.
Being well is a reason to review treatment, not automatically to reduce it.

Acute efficacy is not relapse prevention

Acute trials measure symptom change and prevention trials measure later relapse or recurrence, so evidence from one phase does not establish benefit in the other.

In bipolar illness, agents differ in their protection against mania and against depression.
Abrupt discontinuation can confound prevention trials through withdrawal or rebound.

Kaplan-Meier curves of relapse-free survival over 18 months after randomisation, one for maintenance antipsychotic and one for placebo, with the placebo curve falling faster and crossing 50% at about 9 months. — Illustrative data: a prevention trial measures later relapse over time rather than symptom change, and here the placebo curve falls faster, although when placebo means stopping the drug abruptly some early relapses may reflect withdrawal or rebound. Drawn for the MRCPsychiatrist statistics course

Duration and stopping

Depression commonly needs treatment for at least six months after remission, and longer where recurrence risk is higher.
Reduce gradually, allowing for dose, kinetics, dependence and relapse risk; later steps may need to be smaller.

Feature	Withdrawal	Relapse
Onset	Often soon after reduction, sometimes delayed	Variable, often later
Character	Can include new physical and psychological symptoms	Often resembles prior illness
Course	Brief or prolonged	Variable

After stopping, agree early warning signs and rapid review, involving family or carers with consent.

Revision material for the MRCPsych examinations. Not clinical guidance, and not for use in patient care.