Neuropsychiatry of prolactin: causes and effects

Quality of life in Prolactinoma: A systematic review

BACKGROUND

Prolactinomas are common tumours that significantly reduce quality-of-life (QOL) due to sellar mass effect, secondary hypogonadism, and the peripheral effects of prolactin. Understanding the factors that influence QOL would provide insights into therapeutic targets to optimise patient outcomes and improve wellbeing in prolactinoma.

METHODS

A systematic review was performed in accordance with the PRISMA statement. Studies that reported patient QoL using validated metrics were included. Bias and methodological rigour were assessed using the MINORS criteria.

RESULTS

A total of 18 studies were identified studies were available for review, comprising 877 patients. Most were small cross-sectional studies at high risk of bias. Prolactinoma exhibit worse QOL than healthy controls, particularly mental and psychosocial wellbeing. QOL is also worse than patients with non-functional adenomas, but better than those with Cushing's disease and acromegaly. QOL correlates with prolactin levels, and approaches population baseline with prolonged biochemical control. Dopamine agonists and surgery both improve overall QOL, however improvements are more rapid with surgery.

CONCLUSION

Poor quality of life in prolactinoma is multifactorial, related to biochemical control, side effects of therapy, and sellar mass effect. Targeting persistent symptoms, reducing healthcare costs, and reducing side-effects of therapy are avenues to improving QOL in patients with prolactinoma.

High prolactin levels are associated with more delirium in septic patients

PURPOSES

We investigated whether high prolactin levels were associated with delirium in septic patients because neuropsychiatric disorders are frequently associated with hyperprolactinemia.

MATERIALS AND METHODS

Prolactin levels were measured daily for 4 days in 101 patients with sepsis. Delirium was assessed using the Richmond Agitation Sedation Scale and the Confusion Assessment Method in the ICU.

RESULTS

Delirium developed in 79 patients (78%) and was more common in patients older than 65 years. Prolactin levels were higher in patients with delirium than in those without over the 4 days of observation (P = .032). In patients with delirium, higher prolactin levels were associated with a lower incidence of nosocomial infection (P = .006). Multivariable logistic regression showed that the Sequential Organ Failure Assessment score at intensive care unit admission (odds ratio, 1.24; 95% confidence interval, 1.04-1.48; P = .002) and the combined effect of prolactin levels with age (odds ratio, 1.018; 95% confidence interval, 1.01-1.031; P = .006) were associated with the development of delirium.

CONCLUSIONS

High prolactin levels may be a risk factor for delirium in septic patients.

[Etiopathogeny of the delusion of pregnancy using a literature review: Role of hyperprolactinemia and application of the theory of abductive inference]

INTRODUCTION

Delusions of pregnancy are not well known. The delusion of pregnancy is defined as the belief of being pregnant despite factual evidence to the contrary. The clinical picture is heterogeneous (duration, mechanisms, topics and pre-existing psychiatric disorders). Several causes have been proposed to explain the occurrence of the delusions of pregnancy: cenesthetic theory, hyperprolactinemia, polydipsia and psychodynamic conflicts. Hyperprolactinemia is an interesting hypothesis (physiologic increase during pregnancy and similar manifestations in the course of gestation). The abductive inference theory is a probabilistic model that can clarify the role of hyperprolactinemia in the delusions of pregnancy. The purpose of this paper is to study the role of hyperprolactinemia in the delusions of pregnancy using a literature review. The abductive inference model is used to specify the etiopathogeny of this pathology.

METHODS

A research in Medline, Sudoc, BIUM and PSYLINK using the following key words "delusional pregnancy" or "delusion of pregnancy" and "hyperprolactinemia" was conducted.

RESULTS

Three articles (case reports) about delusions of pregnancy associated with hyperprolactinemia were found. The cases have some similitudes. First of all, they have similar chronology: delusion appears at the same time as hyperprolactinemia and resolves with biological normalization. Secondly, hyperprolactinemia is always caused by a neuroleptic (haloperidol, olanzapine, risperidone). Concerning pre-existing disorders, a psychiatric pathology for each case was found (schizophrenia, schizo-affective disorder and bipolar disorder). Chronology, reproductivity and reversibility are strong arguments to involve hyperprolactinemia in the delusions of pregnancy (Bradford Hill criteria). Furthermore, this association is biologically plausible: physiologic increase during pregnancy (gestational signal), similar symptoms to those during pregnancy and the role in parental behavior (parental signal). Nevertheless, not everyone with hyperprolactinemia will develop a delusion of pregnancy; the interaction is more complex (non linear); the theory of abductive inference clarifies this relationship.

THEORY OF ABDUCTIVE INFERENCE

Abductive inference is a probabilistic model whose goal is to explain the occurrence of delusional beliefs. The first factor is the abnormal data. The second factor is the cognitive process (abductive inference), which uses Bayes' theorem to select the most likely hypothesis to explain the abnormal data. In the delusion of pregnancy, abnormal data is the hyperprolactinemia, signal of gestation without pregnancy. Hypotheses in order to explain this signal are then produced (pregnancy or no pregnancy). In the second part, probabilities associated with each hypothesis, given the hyperprolactinemia, are compared. Since hyperprolactinemia is a gestational signal, the pregnancy hypothesis is most likely. Probabilities associated with each hypothesis without taking hyperprolactinemia into account are compared (prior probability). Since any element of reality indicates a pregnancy, the absence of pregnancy is most likely. In the last step, the posterior probability is calculated using the first two comparisons. The probability associated with the pregnancy hypothesis (taking into account hyperprolactinemia) is relatively higher than the probability associated with the no-pregnancy hypothesis (without taking into account hyperprolactinemia). So, the posterior probability associated with the pregnancy hypothesis is more likely than the posterior probability associated with the no-pregnancy hypothesis. Thus, the subject believes in a pregnancy.

CONCLUSION

The research and the treatment of hyperprolactinemia must be conducted when faced with a delusion of pregnancy.

Paternal deprivation prior to adolescence and vulnerability to pituitary adenomas

It has been reported that women with prolactinoma were exposed, early in life, to an environment characterized by an absent or violent father. The present study was designed to evaluate whether paternal absence or violent paternal behavior were more prevalent in patients with pituitary adenomas (prolactinoma, acromegaly, non-secreting adenoma and Cushing's disease) compared to a control population. We conducted an observational case-control multicenter study. We interviewed 395 patients with prolactinoma (296 females and 99 males), 130 with acromegaly (87 females and 43 males), 237 with non-secreting adenoma (144 females and 93 males) and 68 with Cushing's disease (61 females and 7 males) and 365 patients from the same clinics with nodular thyroid disease or lymphocytic thyroiditis with euthyroidism as controls. Violent or absent fathers were significantly more prevalent in patients with prolactinoma or acromegaly than in controls (P = 0.001 and P = 0.002, respectively) but not in patients with non-secreting adenoma or corticotrophinoma. Absent fathers in prolactinoma and acromegaly versus controls: P = 0.001 and P = 0.119. Violent fathers in prolactinoma and acromegaly versus controls: P = 0.069 and P = 0.001. The prevalence of absent or violent fathers was also significantly higher in prolactinoma and acromegaly when compared to non-secreting adenoma (P = 0.039 and P = 0.033, respectively). Paternal deprivation before adolescence may be a risk factor for prolactinoma and acromegaly but not for non-secreting pituitary adenomas or Cushing's disease.

Quality of life in women with microprolactinoma treated with dopamine agonists

OBJECTIVES

To evaluate QOL in women with microprolactinomas treated with dopamine agonists, comparing the patients with normal versus those with elevated prolactin levels, and to identify clinical and biochemical influences on patients' QOL.

MATERIAL AND METHODS

A cross-sectional evaluation was performed in two University referral centers. Fifty women with microprolactinoma answered the SF-36 questionnaire by the time of their clinical evaluation. Their biochemical analysis included PRL, estradiol, testosterone, and SHBG. Fifty women of similar age distribution served as controls.

RESULTS

Patients had lower scores than controls in all SF-36 categories: physical functioning, physical role, pain, general health, vitality, social functioning, emotional aspect, and mental health. Within the patients' group, the ones with normal PRL levels had higher scores than those with high PRL levels in all categories but the physical role. The physical functioning score correlated with the free androgen index, while the pain, vitality, social functioning, emotional aspect, and mental health scores were associated with the prolactin levels obtained at study entry.

CONCLUSIONS

QOL is impaired in women with microprolactinoma treated with dopamine agonists, and was inversely associated with the PRL levels. This latter finding reinforces the importance of providing adequate disease control for these patients in order to avoid the adverse consequences of hyperprolactinemia on QOL.

Effect of hyperprolactinemia in male patients consulting for sexual dysfunction

INTRODUCTION

The physiological role of prolactin (PRL) in male sexual function has not been completely clarified.

AIM

The aim of this study is the assessment of clinical features and of conditions associated with hyperprolactinemia in male patients consulting for sexual dysfunction.

METHODS

A consecutive series of 2,146 (mean age 52.2 +/- 12.8 years) male patients with sexual dysfunction was studied.

MAIN OUTCOME MEASURES

Several hormonal and biochemical parameters were studied along with validated structured interviews (ANDROTEST and the Structured Interview on Erectile Dysfunction [SIEDY]). Mild hyperprolactinemia (MHPRL; PRL levels of 420-735 mU/L or 20-35 ng/mL) and severe hyperprolactinemia (SHPRL, PRL levels >735 mU/L, 35 ng/mL) were considered.

RESULTS

MHPRL and SHPRL were found in 69 (3.3%) and in 32 (1.5%) patients, respectively. Mean age and the prevalence of gynecomastia were similar in the two groups and in subjects with normal prolactin values. MHPRL was not confirmed in almost one-half of the patients after repetitive venous sampling. Hyperprolactinemia was associated with the current use of antidepressants, antipsychotic drugs, and benzamides. SHPRL was also associated with hypoactive sexual desire (HSD), elevated thyrotropin (TSH), and hypogonadism. The association between HSD and SHPRL was confirmed after adjustment for testosterone and TSH levels, and use of psychotropic drugs (hazard ratio [HR] = 8.60[3.85-19.23]; P < 0.0001). In a 6-month follow-up of patients with SHPRL, testosterone levels and sexual desire were significantly improved by the treatment.

CONCLUSIONS

Our data indicate that SHPRL, but not MHPRL, is a relevant determinant of HSD. Gynecomastia does not help in recognizing hyperprolactinemic subjects, while the use of psychotropic medications and HSD are possible markers of disease. In the case of MHPRL, repetitive venous sampling is strongly encouraged.

Effects of antipsychotics on sexual and endocrine function in women: implications for clinical practice

Typical antipsychotic agents are commonly associated with hyperprolactinemia, which, in turn, leads to sexual dysfunction. The mechanism of action underlying this clinical phenomenon is mediated by the dopamine-blocking action of typical antipsychotic medications, which results in excessive prolactin secretion and secondary effects on gonadal function. This antipsychotic-induced sexual dysfunction is unacceptable to patients and is associated with nonadherence to medication, impacting on the overall clinical outcome and treatment success. Development of first-line atypical antipsychotic agents that do not affect prolactin production is therefore an important advance for patients requiring long-term antipsychotic therapy.

Prolactin, psychological stress and environment in humans: adaptation and maladaptation

Non-puerperal lactation and/or hyperprolactinemia in humans have been related to psychological variables in a variety of ways: (1) Non-puerperal nursing; (2) Pseudopregnancy; (3) Rapid weight gain; (4) Psychogenic galactorrhea; (5) Acute prolactin responses to psychological stress; (6) High prolactin levels in persons who cope passively in real life stress situations; (7) Paternal deprivation in women with pathological hyperprolactinemia; (8) Clinical onset of prolactinomas following life-events. Publications on the above subjects are scattered in the literature as curiosities, anecdotal case-reports or unexplained associations, as there is no theoretical frame of reference to accommodate them. We propose that prolactin is a component of a biological, "maternal", subroutine, adaptive to the care of the young, which promotes accumulation of fat for the extraordinary expenses of pregnancy and lactation, the production of milk and maternal behavior. In an attempt to characterize the stimuli responsible for the activation of the maternal subroutine in the absence of pregnancy we studied the hormonal profiles of female volunteers during three types of sessions under hypnosis: (1) Relaxation-only, control sessions; (2) Sessions in which a fantasy of "nursing" was induced; (3) Sessions of evocations of memories. Prolactin surges were related to the evocation, with rage, of humiliating experiences, but not with the fantasy of nursing. Cortisol surges were related to surprise and shock and were negatively associated with prolactin. In conclusion--Prolactin and cortisol are measurable markers of two different, and alternative, coping strategies to "psychological stress".

Acute psychological stress simultaneously alters hormone levels, recruitment of lymphocyte subsets, and production of reactive oxygen species

Very little is known about the effects of acute psychological stress on the production of reactive oxygen species (ROS) by human phagocytic cells and the interplay between subjectively perceived stress, mediating hormones, variations in the number of peripheral leukocytes and ROS production. We measured psychological reactions, cardiovascular parameters, plasma catecholamines, plasma prolactin and cortisol as well as peripheral lymphocyte subsets in 13 experimental subjects undergoing a brief psychological stressor, and production of ROS, as indicated by chemiluminescence (CL), in stressed subjects and in healthy controls. The stressor elevated anger (p<0.01) and cardiovascular activation (p<0.01). There were significant changes in plasma levels of cortisol (p<0.01) and prolactin (p<0.001). During psychological stress natural killer (NK) cells (p<0.01) and CD8/CD38 cells (p<0.05) increased and returned to baseline only 25 minutes later. Significant changes in the number of naive CD4+/CD45RA+ (p<0.01) and antigen-experienced CD8+/CD45RO+ T cells (p<0.05) occurred. Subjects with stronger cardiovascular reaction showed higher stress-related plasma levels of norepinephrine (p<0.05) and were mainly responsible for the increase in NK cells. We observed a significantly reduced production of ROS following the stress test (p<0.05). Our results show that psychological stress is expressed simultaneously on psychological, hormonal and immunological levels of the organism. We show the existence of a circadian rhythm leading to a pronounced increase in CL during the morning hours. This first study taking this circadian rhythm in account revealed a significant suppressive effect of stress on ROS production.

Increased body weight associated with prolactin secreting pituitary adenomas: weight loss with normalization of prolactin levels

OBJECTIVE

Hyperprolactinaemia in humans may be associated with a high prevalence of obesity but the nature of this link is poorly defined. The aim of this study was to establish the relationship between hyperprolactinaemia and body weight in patients with prolactin-secreting pituitary tumours.

DESIGN

We conducted a retrospective study of prolactinoma patients treated at the Endocrine Institute of the Tel Aviv Medical Center, Israel, during the period 1989-1996. Patients with clinically non-functioning pituitary macroadenomas (NFA) served as the control group. Data on demographic parameters, body weight before and during treatment, clinical presentation including history of weight fluctuations, tumour size as measured by computed tomography or magnetic resonance imaging, modalities and response to treatment, and pituitary function before and during treatment were recorded from medical files.

PATIENTS

Forty-two patients with prolactinomas (PR) and 36 patients with clinically non-functioning macroadenomas (NFA) comprised the study population.

RESULTS

Mean weight was 93 +/- 3.4 kg and 78 +/- 2.7 kg in male patients with PR and NFA respectively (P = 0.0007). Recent weight gain (8 to 22 kg) was a presenting symptom in 13 PR patients, whereas only one NFA patient had this clinical presentation (P = 0.001). Seventeen PR patients lost weight (mean change -8.3 +/- 1.5 kg, range -2-28 kg), during prolactin lowering therapy, 11 of whom had entirely normalized prolactin levels. Fourteen of the 18 patients who did not lose weight still had elevated prolactin levels (P = 0.01). Weight loss in patients with PR could not be attributed to altered pituitary function nor to compression of the third ventricle. In contrast to PR, no significant weight loss was observed in NFA patients.

CONCLUSION

Weight gain and elevated body weight are frequently associated with prolactinomas regardless of a mass effect on the hypothalamus or pituitary function. In this series, weight loss was recorded in 70% of prolactinomas patients and in 90% of male patients who normalized their prolactin levels. We propose the inclusion of hyperprolactinaemia in the differential diagnosis of endocrine obesity and weight gain.

Endocrine and psychological evaluation of women with recent weight gain

A group of 13 consecutive regularly menstruating women who gained at least 5 kg the previous year (Group I) was compared to a control group of similar age, parity, and social class (Group II). The two groups were similar in estimated and observed food intakes; pre- and postprandial gastrin levels; hourly 24-h profiles of cortisol and insulin; urinary cortisol and 17-hydroxycorticosteroids. Group I had higher serum prolactin concentrations at all times than Group II (mean values 14.60 micrograms/l vs. 8.84 micrograms/l; p = .0121). Galactorrhea was observed in 5 women from Group I and in none of the women from Group II (p < .05). Group I also differed from Group II in a higher incidence of meaningful life-events the year preceding the study, higher prevalence of sexual dysfunction (9/13 vs. 4/13; p < .01) and higher indexes (p < .05) of several parameters in the MMPI and SCL 90. Median serum cortisol and prolactin concentrations were negatively correlated, both in Group I (R = -.669; p = .012) and in the whole sample (R = -.453; p = .0298). It is suggested that the rapid weight gain is part of a neuroendocrine response to environmental stimuli also characterized by hyperprolactinemia. The significant negative correlation between serum prolactin and cortisol indicates that this response differs from, and is possibly an alternative to, the sympathoadrenal "stress" response.

Psychosocial factors, female fertility and pregnancy: a prospective study--Part I: Fertility

The aim of the study was to determine prospectively whether psychosocial, personality-related or stress factors have influence on fertility. Initially 191 healthy nulliparas without a history of infertility who were planning to have children were studied gynecologically and by psychiatric examination. Life changes and changes in psychosocial stress were monitored throughout the study period of 6 months at regular intervals. The following factors turned out to be associated with higher than average fertility in the final follow-up sample of 180 women: looking younger than one's actual age, no fluctuation in body weight before pregnancy, low consumption of coffee, low score of psychosomatic symptoms, being the youngest sibling, low number of negative life changes, younger than spouse, having phobic traits, and customarily religious. There was no clearcut association between low fertility and deviations in personality factors.