10.2 Depression, Anxiety & Psychosis

10.2 Depression, Anxiety & Psychosis

Quick Answer: SSRIs/SNRIs take weeks for full effect — counsel persistence, and monitor early for agitation, worsening mood and suicide risk (especially young people). Know serotonin syndrome red flags with serotonergic combinations. Benzodiazepines are short-term tools with dependence risk. Antipsychotics need metabolic monitoring. Lithium needs levels + renal + thyroid concepts. St John’s wort is a major inducer/interactor, not a harmless tea.

Mental health medicines are high-volume community supplies and high-stakes exam content under 3.1–3.3: assess the person, implement a safe plan, and monitor for efficacy and harm. Use non-judgemental communication; stigma reduces adherence and disclosure of suicidal thoughts.

Depression and anxiety — SSRI and SNRI foundations

Selective serotonin reuptake inhibitors (SSRIs) (e.g. sertraline, escitalopram, fluoxetine, citalopram, paroxetine) and serotonin–noradrenaline reuptake inhibitors (SNRIs) (e.g. venlafaxine, desvenlafaxine, duloxetine) are first-line pharmacological options for many people with major depression and for several anxiety disorders, alongside psychological therapies.

Onset delay — set expectations

Therapeutic benefit is often delayed 2–4 weeks (sometimes longer for full response), while early adverse effects (nausea, headache, sleep change, anxiety surge, sexual dysfunction) can appear within days. Exam-critical counselling:

• Do not stop after a few days because “it isn’t working yet”.
• Some people feel more anxious or activated early — contact the prescriber if severe.
• Nausea often settles; taking with food may help for some agents (check product advice).
• Sexual dysfunction is common and under-reported — invite open discussion; do not dismiss.
• Discontinuation symptoms can occur if stopped abruptly (especially shorter half-life agents such as paroxetine or venlafaxine) — taper under medical advice.

Suicide risk monitoring early in treatment

Antidepressants can be associated with increased suicidal thinking and behaviour early in treatment, particularly in children, adolescents and young adults. Pharmacists should:

• Ask about mood change, agitation, restlessness, or new suicidal thoughts at initiation and early supply.
• Encourage involvement of trusted supports where appropriate and consented.
• Ensure the patient knows how to access urgent help (GP, crisis services, emergency department).
• Never trivialise statements of hopelessness; escalate appropriately while respecting privacy frameworks.

This is not a reason to refuse all antidepressants; it is a reason for informed monitoring and safety-netting.

Other practical SSRI/SNRI points

Serotonin syndrome — recognise and act

Serotonin syndrome is a potentially life-threatening excess of serotonergic activity. Risk rises with combinations (e.g. SSRI + MAOI — contraindicated patterns; SSRI + tramadol; SSRI + triptan in some contexts; SSRI + St John’s wort; overdose).

Clinical pattern (conceptual triad):

1. Mental status — agitation, confusion, restlessness
2. Autonomic — sweating, tachycardia, hypertension/lability, hyperthermia, diarrhoea
3. Neuromuscular — tremor, hyperreflexia, clonus, rigidity

Pharmacy action: treat as urgent medical emergency if suspected; stop further serotonergic doses pending medical assessment; document interacting medicines carefully when reviewing new prescriptions.

Benzodiazepines — short-term use and dependence

Benzodiazepines (e.g. diazepam, temazepam, oxazepam, alprazolam, clonazepam) enhance GABA activity and are used for acute anxiety, alcohol withdrawal (specialist pathways), seizures, and short-term insomnia in selected cases.

Core principles for Australian community pharmacy:

• Prefer lowest effective dose and shortest duration consistent with the indication.
• Dependence, tolerance, and withdrawal (including rebound anxiety/insomnia, and rarely seizures with abrupt stop after prolonged use) are real risks.
• Adverse effects: sedation, falls (especially older adults), cognitive impairment, driving impairment, and respiratory depression risk with opioids/alcohol.
• S4 medicines with prescription requirements; some jurisdictions have additional real-time prescription monitoring considerations for high-risk combinations.
• Non-drug strategies (sleep hygiene, CBT for insomnia/anxiety) should be reinforced where appropriate.

Exam distractors often suggest long-term “as needed forever” benzodiazepines as first-line chronic anxiety care — that is usually the wrong framing when psychological therapy and SSRI/SNRI strategies are more appropriate long-term options.

Psychosis and antipsychotics — metabolic monitoring

Antipsychotics treat schizophrenia spectrum disorders, acute psychosis, bipolar mania (selected agents), and sometimes off-label behavioural symptoms (specialist caution). They divide broadly into first-generation (typical) and second-generation (atypical) agents, with overlapping risks.

Metabolic syndrome risk

Many second-generation agents (e.g. olanzapine, quetiapine, clozapine — special status) promote weight gain, dyslipidaemia, and insulin resistance. Pharmacy role:

• Support baseline and periodic monitoring concepts: weight/BMI, waist, blood pressure, fasting glucose or HbA1c, lipids (local protocols and AMH).
• Counsel lifestyle: diet, activity, smoking cessation support.
• Flag rapid weight gain early to the prescriber — do not wait for frank diabetes.

Other antipsychotic safety themes

Clozapine has intensive blood monitoring for agranulocytosis and other special requirements — exam items usually test that it is not a routine unsupervised community initiation, not detailed titration tables.

Lithium — monitoring concepts

Lithium is a highly effective mood stabiliser for bipolar disorder with a narrow therapeutic index.

Monitoring pillars (concepts, exact target ranges from AMH/local lab):

• Serum lithium levels — trough timing relative to dose; interpret with clinical status
• Renal function — lithium can impair kidneys long-term; dehydration raises levels
• Thyroid function — hypothyroidism risk
• Electrolytes / calcium as indicated

Toxicity clues: coarse tremor, diarrhoea, vomiting, ataxia, confusion, severe drowsiness. Precipitants include dehydration, NSAID use, ACE inhibitors/ARBs, thiazides, low-salt diets, and acute illness. Counsel patients to maintain fluid intake, seek advice before new OTC NSAIDs, and not double doses after missed tablets without advice.

St John’s wort and complementary serotonergic products

St John’s wort (Hypericum perforatum) induces CYP3A4 and P-glycoprotein, reducing concentrations of many medicines (e.g. some oral contraceptives → pregnancy risk, some immunosuppressants, some antiretrovirals, warfarin variability, certain anticancer agents). It also has serotonergic activity and can contribute to serotonin syndrome with antidepressants.

Pharmacy exam stance:

• Ask about complementary medicines routinely.
• Do not recommend St John’s wort as a casual add-on to prescription antidepressants.
• Warn that “natural” does not mean interaction-free.

Integrated counselling approach

Mental health supply is more than handing over a box. Confirm the patient knows what the medicine is for, when benefit is expected, what adverse effects to report, how long to continue, and who to contact if mood worsens. Document interventions and collaborate with GPs, psychiatrists, and mental health services within privacy rules. For Intern Written items, the highest-scoring answers combine empathy, pharmacology, and safety monitoring rather than pure drug-name recall.