Perinatal Psychiatric Care

Postpartum psychosis is an acute, severe mental health condition that typically emerges within the first two weeks after childbirth. It is characterized by rapid onset of psychotic symptoms such as delusions, hallucinations, disorganized thinking, and extreme mood swings. For example, a new mother may suddenly believe that a stranger is trying to harm her baby, or she may hear voices urging her to act in dangerous ways. The urgency of recognition cannot be overstated; prompt assessment and intervention are critical to protect both mother and infant.

Perinatal period refers to the time frame extending from conception through the first year after birth. This period is divided into three phases: antepartum (pregnancy), intrapartum (labor and delivery), and postpartum (the weeks and months following birth). Understanding the perinatal timeline helps clinicians anticipate when certain psychiatric conditions are most likely to appear and tailor screening accordingly.

Peripartum is a term often used interchangeably with perinatal, but it specifically emphasizes the interval surrounding childbirth, usually defined as the last trimester of pregnancy through the first six weeks after delivery. In clinical documentation, precise use of peripartum versus postpartum terminology can affect coding, insurance reimbursement, and research reporting.

Antepartum denotes the period before birth. Although most discussions of postpartum psychosis focus on the postnatal phase, many risk factors develop during the antepartum phase. For instance, a woman with a history of bipolar disorder who experiences mood instability during pregnancy may be at heightened risk for a postpartum psychotic episode.

Postpartum is the period after delivery. In the context of psychosis, the first two weeks are considered the highest risk window, with symptoms potentially escalating to a full psychotic break within days. Health professionals must maintain vigilance during this period, even when the mother appears physically well.

Psychosis is a broad term that describes a loss of contact with reality, manifested as delusions, hallucinations, or severely disorganized thought. In perinatal care, psychosis is rare but carries a high morbidity and mortality risk. Differentiating psychosis from other mood disorders requires careful mental status examination and often involves collaboration with a psychiatrist.

Mania is a state of abnormally elevated mood, increased energy, and decreased need for sleep. In postpartum psychosis, mania may coexist with psychotic features, creating a mixed picture that can be confusing to clinicians unfamiliar with the condition. A mother might display rapid speech, grandiose ideas about her parenting abilities, and a refusal to sleep, all while experiencing delusional thoughts.

Delusion is a fixed, false belief that is resistant to contrary evidence. Common delusions in postpartum psychosis include themes of persecution (e.g., “someone wants to steal my baby”), grandiosity (e.g., “I am a special mother chosen to save the world”), or somatic concerns (e.g., “my baby is possessed”). Recognizing delusional content quickly can guide risk assessment, especially when the belief involves harm to the infant.

Hallucination is a perception in the absence of external stimulus. Auditory hallucinations are most frequent in postpartum psychosis, often taking the form of commanding voices that urge the mother to act in ways that may endanger herself or her child. Visual hallucinations, though less common, may involve seeing nonexistent figures near the infant’s crib.

Mood disorder is a broad classification that includes depression and bipolar disorder. While postpartum depression is more common, postpartum psychosis is most strongly associated with bipolar disorder, particularly bipolar I. Understanding a patient’s previous mood disorder history is essential for risk stratification.

Bipolar disorder is a chronic condition marked by alternating periods of depression and mania or hypomania. Women with bipolar disorder have a markedly increased risk of postpartum psychosis, especially if they discontinue mood stabilizers during pregnancy. A practical challenge is balancing fetal safety with the mother’s psychiatric stability; many clinicians opt for a carefully monitored continuation plan.

Schizophrenia is a chronic psychotic disorder that can surface for the first time in the perinatal period, though this is uncommon. When it does occur, it may be misdiagnosed as postpartum psychosis. Distinguishing features include a longer duration of symptoms and a lack of clear temporal relation to childbirth.

Affective disorder encompasses mood-related diagnoses such as depression and bipolar disorder. In perinatal psychiatry, the term helps clinicians frame the emotional context of psychotic symptoms, especially when they are mood-congruent (e.g., depressive delusions) versus mood-incongruent (e.g., bizarre, unrelated delusions).

Risk factors are variables that increase the likelihood of developing postpartum psychosis. They include a personal or family history of bipolar disorder, previous postpartum psychotic episodes, abrupt discontinuation of mood stabilizers, severe sleep deprivation, obstetric complications, and psychosocial stressors such as lack of support. A thorough risk assessment must incorporate both biological and psychosocial domains.

Precipitants refer to immediate triggers that may precipitate an episode. Common precipitants in postpartum psychosis include hormonal shifts after delivery, intense fatigue, and the overwhelming demands of newborn care. For example, a mother who has been awake for 48 hours straight and is caring for a newborn may experience a rapid decompensation.

Genetic predisposition highlights the role of inherited vulnerability. Twin studies have shown that first-degree relatives of women with postpartum psychosis have a higher incidence of mood disorders. Genetic counseling may be offered to families with a strong history of bipolar disorder.

Hormonal changes involve rapid fluctuations in estrogen, progesterone, and cortisol after delivery. These hormonal shifts can destabilize neurotransmitter systems, contributing to the onset of psychosis. While the exact mechanisms remain unclear, clinicians should be aware that hormonal fluctuations are a biologically plausible trigger.

Sleep deprivation is a well-documented precipitant. Newborns often require feeding every two to three hours, leading to fragmented sleep for the mother. Even short periods of severe sleep loss can precipitate manic or psychotic symptoms in vulnerable individuals. Practical interventions include arranging in‑home support to allow the mother to obtain restorative sleep.

Stressors encompass life events that increase psychological pressure. These may include marital conflict, financial hardship, or the loss of a loved one during the perinatal period. Stressful circumstances can exacerbate underlying mood instability and increase the risk of psychosis.

Obstetric complications such as preeclampsia, emergency cesarean section, or severe postpartum hemorrhage have been linked to higher rates of postpartum psychosis. The physical trauma and associated medical interventions can amplify stress and hormonal dysregulation.

Trauma includes both prior trauma (e.g., childhood abuse) and perinatal trauma (e.g., a frightening delivery). A history of trauma may sensitize the brain’s stress response systems, making postpartum psychiatric decompensation more likely.

Postpartum blues is a transient mood disturbance affecting up to 80 % of new mothers, typically resolving within two weeks. It is characterized by tearfulness, irritability, and mild anxiety. Distinguishing postpartum blues from psychosis is crucial: blues do not involve delusions or hallucinations, and they do not impair functioning to the degree seen in psychosis.

Postpartum depression is a mood disorder that can develop within the first year after birth, marked by persistent sadness, loss of interest, guilt, and sometimes suicidal ideation. While depression and psychosis can coexist, depression alone does not involve psychotic features. Screening tools such as the Edinburgh Postnatal Depression Scale help differentiate these conditions.

Differentiation of postpartum psychosis from other perinatal mood disorders requires a systematic approach, including a focused mental status exam, collateral information from family, and, when needed, psychiatric consultation. The presence of delusions or hallucinations is the key distinguishing factor.

Assessment involves a comprehensive evaluation that includes medical history, psychiatric history, current symptomatology, risk assessment for self‑harm or infant‑harm, and physical examination. Structured tools such as the Brief Psychiatric Rating Scale can quantify severity and monitor treatment response.

Screening tools are standardized questionnaires used to identify women at risk. The Edinburgh Postnatal Depression Scale (EPDS) is widely used for depression, while the Mood Disorder Questionnaire (MDQ) can screen for bipolar tendencies. Although no single tool perfectly captures psychosis risk, combining multiple instruments improves detection.

Edinburgh Postnatal Depression Scale consists of ten items scored from 0 to 3, with a total score of 13 or higher indicating possible depression. While EPDS does not directly assess psychosis, certain items (e.g., “the thought that I could hurt myself”) may raise red flags prompting further evaluation.

Brief Psychiatric Rating Scale is a clinician‑rated instrument that assesses ten symptom domains, including conceptual disorganization, anxiety, and hostility. Scores above 31 suggest severe psychopathology and may indicate the need for urgent intervention.

Clinical interview is the cornerstone of psychiatric assessment. It should be conducted in a calm, private setting, with open‑ended questions that allow the mother to describe her experiences without judgment. Interviewers should avoid leading language and instead use neutral prompts such as “Can you tell me more about what you’re hearing?”

Mental status exam evaluates appearance, behavior, speech, mood, affect, thought process, thought content, perception, cognition, insight, and judgment. In postpartum psychosis, thought content (delusions) and perception (hallucinations) are often disturbed, while insight is typically limited.

Safety planning is an essential component of care. It includes identifying warning signs, establishing emergency contacts, arranging for a safe environment for the infant, and, when necessary, planning for involuntary admission. A clear, written safety plan can empower the mother and her support network.

Mother‑infant bonding refers to the emotional connection that develops between a caregiver and her newborn. Psychosis can disrupt this process, leading to impaired attachment and long‑term developmental consequences for the child. Early intervention aims to preserve bonding through supportive therapy and, when needed, supervised caregiving.

Attachment theory describes the emotional bond that forms between a child and primary caregiver. Secure attachment is associated with better outcomes, while disorganized attachment may result from maternal psychosis. Clinicians should assess attachment quality and provide resources such as infant‑parent psychotherapy.

Lactation considerations are central to medication decisions. Many antipsychotic and mood‑stabilizing medications are excreted in breast milk, potentially affecting the infant. However, the benefits of breastfeeding must be weighed against the risks of medication exposure. Shared decision‑making with the mother, pediatrician, and psychiatrist is essential.

Medication safety involves evaluating the risk‑benefit profile of pharmacologic agents during lactation. For example, haloperidol has relatively low milk transfer, while lithium has higher levels and may require infant monitoring of thyroid and renal function. Detailed counseling helps mothers make informed choices.

Antipsychotics are the primary pharmacologic treatment for acute psychosis. First‑generation agents such as haloperidol and second‑generation agents such as olanzapine are commonly used. Dosage must be individualized, and side effects—particularly extrapyramidal symptoms—require close monitoring.

Lithium is a gold‑standard mood stabilizer for bipolar disorder and can be effective in preventing postpartum psychosis recurrence. However, lithium crosses into breast milk and may cause neonatal toxicity. If lithium is continued, infant serum lithium levels should be checked regularly, and the infant’s thyroid and renal function should be monitored.

Valproate is contraindicated in pregnancy due to teratogenicity and is generally avoided in the postpartum period if the mother intends to breastfeed. Alternative mood stabilizers such as lamotrigine may be considered, though lamotrigine’s efficacy for acute psychosis is limited.

Breastfeeding decisions should be guided by a risk‑benefit analysis. In many cases, the mother’s psychiatric stability outweighs the potential medication exposure risk. When breastfeeding is not possible, support for formula feeding should be provided without judgment.

Pharmacokinetics during the postpartum period are altered due to changes in plasma volume, renal clearance, and hepatic metabolism. For instance, the half‑life of haloperidol may be shortened, necessitating dose adjustments. Clinicians should stay informed about these changes to avoid sub‑therapeutic or toxic levels.

Non‑pharmacologic interventions complement medication and include psychoeducation, psychotherapy, sleep hygiene strategies, and social support. Evidence suggests that early psychoeducation can reduce relapse rates by improving medication adherence and recognizing early warning signs.

Psychotherapy options include cognitive‑behavioral therapy (CBT), interpersonal therapy (IPT), and family therapy. CBT can help patients challenge delusional beliefs, while IPT focuses on role transitions and loss, which are salient during the perinatal period. Family therapy addresses the impact of psychosis on the wider support system.

CBT techniques such as reality testing, thought challenging, and behavioral activation are adapted to the postpartum context. For example, a therapist may help a mother test the reality of a delusional belief by examining evidence and developing coping statements.

Family therapy involves the mother, partner, and sometimes extended family members. It provides a safe space to discuss fears, clarify caregiving responsibilities, and develop a unified plan for crisis management. Family involvement often improves adherence to treatment and reduces isolation.

Support groups offer peer‑to‑peer interaction, reducing stigma and providing practical tips. Groups specific to postpartum psychosis allow mothers to share experiences and coping strategies, which can be particularly empowering during recovery.

Crisis intervention is required when a mother poses an imminent risk to herself or her infant. This may involve emergency hospitalization, involuntary admission under mental health legislation, or rapid mobilization of community crisis teams. The goal is to stabilize the mother while ensuring infant safety.

Involuntary admission may be necessary when the mother lacks insight and refuses treatment despite a clear danger. Legal frameworks such as the Mental Health Act guide the process, and clinicians must respect patient rights while prioritizing safety.

Ethical considerations include balancing maternal autonomy with infant protection, respecting cultural values, and ensuring informed consent. When a mother’s capacity is compromised, surrogate decision‑makers or legal guardians may be consulted.

Cultural competence is vital because beliefs about mental illness, motherhood, and treatment vary across cultures. For instance, some cultures may view psychotic symptoms as spiritual experiences, influencing help‑seeking behavior. Clinicians should inquire respectfully about cultural beliefs and integrate them into care plans when possible.

Stigma surrounding postpartum mental illness often delays help‑seeking. Educational campaigns that normalize discussion of postpartum psychosis can reduce stigma. In clinical practice, using non‑judgmental language and emphasizing recovery can mitigate internalized stigma.

Patient autonomy respects the mother’s right to make informed choices about her care. Even when safety concerns arise, clinicians should strive to involve the mother in decision‑making as much as her mental state allows.

Informed consent requires that the mother understand the benefits, risks, and alternatives of treatment options. When psychosis impairs decision‑making capacity, clinicians must document the assessment of capacity and, if necessary, obtain consent from a legally authorized representative.

Multidisciplinary team is the backbone of perinatal psychiatric care. It typically includes an obstetrician, psychiatrist, midwife, pediatrician, mental health nurse, social worker, and, when appropriate, a lactation consultant. Collaboration ensures comprehensive management of both maternal and infant health.

Obstetrician monitors physical recovery from childbirth, screens for obstetric complications, and coordinates medication safety regarding pregnancy‑related physiology.

Psychiatrist leads the diagnostic formulation, prescribes psychotropic medication, and oversees risk management. In many settings, a perinatal psychiatrist with specialized training provides the most nuanced care.

Midwife often serves as the first point of contact for new mothers, offering education on warning signs and facilitating referrals to mental health services.

Pediatrician assesses infant health, monitors for medication exposure effects, and provides guidance on feeding and developmental milestones.

Social worker addresses socioeconomic barriers, connects families to community resources, and assists with housing or financial assistance when needed.

Mental health nurse conducts regular follow‑ups, administers medication, and reinforces psychoeducation.

Community resources such as mother‑baby units, crisis hotlines, and home‑visiting programs extend care beyond the hospital setting. These services can be lifesaving when a mother experiences a relapse after discharge.

Relapse prevention strategies focus on identifying early warning signs, maintaining medication adherence, ensuring adequate sleep, and establishing a strong support network. A relapse plan often includes a schedule for regular psychiatric appointments and a list of emergency contacts.

Follow‑up care should be scheduled within a week of discharge and continue weekly for at least the first month, then bi‑weekly or monthly based on stability. Follow‑up visits assess symptom progression, medication side effects, infant health, and caregiving capacity.

Relapse triggers commonly include sleep loss, stress, medication non‑adherence, and hormonal fluctuations associated with subsequent pregnancies. Anticipating these triggers allows clinicians to intervene early.

Sleep hygiene recommendations include establishing a consistent bedtime routine, using nighttime feeding assistance, and limiting caffeine. Even short naps can be beneficial; clinicians should encourage mothers to prioritize rest.

Stress management techniques such as mindfulness, breathing exercises, and brief physical activity can mitigate anxiety and reduce the likelihood of decompensation.

Psychoeducation involves teaching mothers and families about the nature of postpartum psychosis, medication effects, warning signs, and coping strategies. Knowledge empowers families to act swiftly if symptoms recur.

Early warning signs may manifest as subtle changes in mood, increased irritability, or mild sleep disturbance. Recognizing these signs before full psychosis emerges can prevent escalation.

Relapse signs include the reappearance of delusional thoughts, auditory hallucinations, rapid speech, or a marked decline in functioning. Prompt re‑evaluation is necessary when any of these appear.

Emergency contact information should be clearly documented, including the mother’s psychiatrist, local crisis team, and a trusted family member. This list should be reviewed with the mother during discharge planning.

Legal aspects such as the Mental Health Act dictate when involuntary treatment can be initiated. Clinicians must be familiar with local statutes to ensure lawful and ethical practice.

Confidentiality must be maintained, except when there is a clear risk of harm to the infant. In such cases, clinicians have a duty to report to protective services while still protecting as much of the mother’s privacy as possible.

Documentation should be thorough, capturing symptom onset, assessment findings, risk level, treatment decisions, and informed consent discussions. Accurate records are crucial for continuity of care and legal protection.

Outcome measures include symptom severity scales, functional assessments, infant developmental milestones, and quality‑of‑life questionnaires. Tracking outcomes over time informs treatment effectiveness and program improvement.

Quality improvement initiatives may involve auditing screening rates, reducing time to treatment, and enhancing multidisciplinary communication. Continuous feedback loops help refine care pathways for postpartum psychosis.

Research gaps remain in areas such as the optimal duration of prophylactic medication, the role of genetics in predicting risk, and culturally adapted interventions. Encouraging participation in research studies can advance the field.

Perinatal psychiatric emergency is a situation where a mother’s mental state poses an immediate danger. Protocols typically include rapid assessment, stabilization, and safe transfer to a specialized unit. The presence of a neonatology team ensures infant safety during maternal stabilization.

Neonatal monitoring is required when a mother is receiving psychotropic medication. Blood levels, thyroid function, and renal function may be checked in the first weeks of life, especially if lithium or high‑dose antipsychotics are used.

Infant‑parent psychotherapy is a therapeutic modality that focuses on the dyadic relationship, using play and observation to strengthen attachment. It can be particularly beneficial when the mother’s psychosis has disrupted early bonding.

Medication adherence is a frequent challenge due to side effects, fear of medication, or lack of insight. Strategies such as pill organizers, mobile reminders, and involving family members in medication administration can improve adherence.

Side‑effect management includes monitoring for extrapyramidal symptoms, metabolic changes, and sedation. Early identification allows dose adjustments or medication switches before severe complications develop.

Metabolic monitoring is especially important with second‑generation antipsychotics, which can cause weight gain, hyperglycemia, and dyslipidemia. Regular weight checks, fasting glucose, and lipid panels should be incorporated into follow‑up visits.

Risk assessment tools such as the Columbia‑Suicide Severity Rating Scale (C‑SSRS) can be used to evaluate suicidal ideation, which may co‑occur with psychosis. A thorough risk assessment must address both self‑harm and infant‑harm potentials.

Infant safety planning may involve temporary placement with a trusted family member, use of a safe sleep environment, and supervision during high‑risk periods. The goal is to protect the infant while supporting maternal recovery.

Legal guardianship may be required if a mother is deemed incapable of caring for her child due to severe psychosis. Courts may appoint a temporary guardian until the mother regains capacity.

Community mental health teams often provide home visits, medication administration, and psychosocial support. Their involvement can reduce readmission rates and promote stability.

Telepsychiatry has emerged as a valuable tool for delivering care to mothers in remote areas. Video consultations allow for real‑time assessment of mood, thought content, and infant interaction, while reducing travel barriers.

Digital health tools such as mood‑tracking apps can help mothers record symptoms, sleep patterns, and medication adherence. Clinicians can review these data to identify trends and intervene early.

Barriers to care include lack of insurance coverage, limited mental health providers specialized in perinatal care, and geographic isolation. Addressing these barriers requires policy advocacy and resource allocation.

Insurance considerations often dictate the availability of inpatient versus outpatient services. Clinicians should be familiar with reimbursement codes for postpartum psychosis to ensure patients receive appropriate coverage.

Policy advocacy involves lobbying for legislation that mandates universal screening for perinatal mental health disorders and funds specialized mother‑baby units.

Mother‑baby units are inpatient settings where the mother and infant stay together, allowing for treatment of the mother while preserving the mother‑infant bond. These units provide a safe environment for medication stabilization and therapy.

Discharge planning must be comprehensive, incorporating medication instructions, follow‑up appointments, emergency contacts, and infant care guidelines. A written discharge summary should be shared with all members of the care team.

Continuity of care is achieved when the same psychiatrist or mental health provider follows the mother through the acute phase, stabilization, and maintenance. Consistency reduces the risk of miscommunication and improves therapeutic alliance.

Stigma reduction initiatives often involve public awareness campaigns, training for primary care providers, and inclusion of mental health education in prenatal classes. Normalizing conversation about postpartum psychosis can encourage early help‑seeking.

Peer support specialists are individuals with lived experience of postpartum psychosis who provide mentorship and advocacy. Their unique perspective can bridge gaps between clinical care and personal recovery.

Family education sessions teach partners and relatives how to recognize warning signs, support medication adherence, and maintain a calm environment for the infant. Education reduces caregiver burden and improves outcomes.

Trauma‑informed care acknowledges that many women have histories of abuse or adverse childhood experiences. Providers should create a safe, predictable environment, ask permission before examinations, and avoid re‑traumatizing language.

Maternal self‑efficacy refers to a mother’s confidence in her ability to care for her infant. Psychosis can erode this confidence; supportive interventions aim to rebuild self‑efficacy through skill building and positive reinforcement.

Infant developmental monitoring is essential because early exposure to maternal psychosis can affect attachment and later emotional regulation. Routine developmental screenings at 2, 6, and 12 months can detect early delays.

Language barriers can impede assessment and treatment. Using professional interpreters and culturally appropriate educational materials ensures accurate communication.

Research methodology in perinatal psychiatry often employs longitudinal cohort studies to track outcomes over time. Understanding study design is important for clinicians interpreting research findings.

Evidence‑based practice integrates the best available research with clinical expertise and patient values. In postpartum psychosis, evidence supports rapid antipsychotic initiation combined with psychosocial support.

Clinical pathways outline step‑by‑step management, from initial screening to discharge. Standardized pathways improve consistency and reduce treatment delays.

Risk‑benefit analysis is a continuous process, especially regarding medication during breastfeeding. Clinicians must weigh the mother’s psychiatric stability against potential infant exposure, documenting the rationale.

Interdisciplinary communication tools such as shared electronic health records facilitate real‑time updates on medication changes, infant health status, and social service involvement.

Case illustration – A 28‑year‑old woman with a known bipolar I disorder stopped lithium during the third trimester, delivered a healthy baby, and within five days began experiencing vivid auditory hallucinations commanding her to “harm the baby.” She also displayed rapid speech and grandiose delusions about her parenting abilities. The midwife identified these symptoms, contacted the on‑call psychiatrist, and the mother was admitted to a mother‑baby unit. Haloperidol was initiated, and a safety plan was established. Her partner received psychoeducation, and a lactation consultant discussed the low milk transfer of haloperidol. After ten days, her symptoms resolved, and she was discharged with close outpatient follow‑up. This case highlights the importance of early detection, multidisciplinary collaboration, medication safety, and family involvement.

Practical application – During a routine 6‑week postpartum visit, a nurse uses the EPDS and adds three supplemental questions about hearing voices, feeling “out of control,” and thoughts of harming the baby. A score of 15 on the EPDS plus a positive response to hearing voices triggers an urgent referral to the perinatal psychiatrist, illustrating how brief screening can catch early psychosis.

Challenges – One major obstacle is the limited availability of specialized perinatal psychiatrists, especially in rural areas. Telepsychiatry can mitigate this gap, but licensing restrictions and internet connectivity may still hinder access. Another challenge is balancing maternal autonomy with infant safety; clinicians must navigate ethical dilemmas when a mother’s capacity is fluctuating. Stigma remains pervasive, often preventing women from disclosing symptoms. Addressing this requires ongoing community education and training for all health professionals who interact with postpartum women.

Implementation strategies – Hospitals can develop protocols that require all postpartum women to be screened for psychosis using a brief tool within 48 hours of delivery. Training sessions for obstetric staff on recognizing psychotic signs improve early identification. Embedding a mental health liaison in labor and delivery units ensures rapid consultation. Additionally, creating a registry of women with prior postpartum psychosis helps track long‑term outcomes and informs preventive care.

Monitoring and evaluation – Key performance indicators include the proportion of postpartum women screened for psychosis, time from symptom onset to treatment initiation, readmission rates within 30 days, and infant developmental scores at 12 months. Regular audits of these metrics guide continuous improvement.

Future directions – Emerging research on biomarkers such as inflammatory cytokines and neuroimaging may eventually enable objective risk stratification. Genetic testing for known bipolar susceptibility loci could inform prophylactic treatment decisions. Integration of artificial intelligence into electronic health records may provide predictive alerts for clinicians based on patterns of sleep loss, medication non‑adherence, and recorded mood symptoms.

Interprofessional education – Training programs that bring together obstetrics, psychiatry, nursing, and social work students foster a shared understanding of postpartum psychosis. Simulated scenarios involving a mother presenting with auditory hallucinations allow learners to practice collaborative assessment and crisis management.

Conclusion omitted as per instruction.**