Aside from the medicine, it is important to be aware of the effects of psychiatric problems on the patient's relationship and address the psychosocial issues.17 Up to 70% of patients with depression have sexual dysfunction, which can affect any phase of sexual activity.18 Reports indicate that 30–80% of women and 45–80% of men with schizophrenia also experience sexual problems.19 In these patients, it may be difficult to distinguish the effects of the illness on sexual function from the effects of the drugs used for treatment.
Antidepressants
Many antidepressants cause sexual difficulties.17,20 Selective serotonin reuptake inhibitors and serotonin noradrenaline reuptake inhibitors inhibit desire, cause erectile dysfunction and decrease vaginal lubrication. They also impair orgasm in 5–71% of patients.18,21,22 This adverse effect is used therapeutically to delay premature ejaculation.
Tricyclic antidepressants inhibit sexual desire and orgasm.23,24 The effects of specific drugs vary depending on their mechanism of action. For example, clomipramine causes orgasmic difficulties in up to 90% of patients, while nortriptyline causes more erectile dysfunction but has less effect on orgasm.25
Monoamine oxidase inhibitors are also associated with sexual dysfunction. Although moclobemide was reported to increase sexual desire,24 the doses used in that study were considered subtherapeutic.
Other antidepressants such as venlafaxine and mirtazapine have variable negative effects on all aspects of sexual function. Initial reports on agomelatine in both male and female patients with major depressive disorder suggested significant antidepressant efficacy without significant sexual adverse effects. However, more recent reviews of the sexual effects are conflicting.26,27
Antipsychotics
Some antipsychotics may affect sexual function more than others (see Table 2).19,28 The only Cochrane review of antipsychotic-induced sexual dysfunction has reported a small number of studies relating to men, but none relating to women.29
Men taking antipsychotics report erectile dysfunction, decreased orgasmic quality with delayed, inhibited or retrograde ejaculation, and diminished interest in sex. Women experience decreased desire, difficulty achieving orgasm, changes in orgasmic quality and anorgasmia. Dyspareunia, secondary to oestrogen deficiency, can result in vaginal atrophy and dryness. Galactorrhea is experienced in both sexes.28
A recent observational study of schizophrenia found that in patients with diminished sexual desire, ziprasidone was preferred over olanzapine.30 The majority of antipsychotics cause sexual dysfunction by dopamine receptor blockade. This causes hyperprolactinaemia with subsequent suppression of the hypothalamic–pituitary–gonadal axis and hypogonadism in both sexes. This decreases sexual desire and impairs arousal and orgasm. It also causes secondary amenorrhoea and loss of ovarian function in women and low testosterone in men.31,32 Although poorly understood, other neurotransmitter pathways including histamine blockade, noradrenergic blockade and anticholinergic effects may also be affected by antipsychotics.
Before commencing dopamine receptor antagonists it is useful to establish a baseline prolactin, as subsequent elevation can then be attributed to the drug. Non-drug induced causes of hyperprolactinaemia such as pituitary tumours should be considered in patients on dopamine receptor antagonists.33

Antiepileptics
Sexual dysfunction is common in patients on antiepileptic drugs.34 Gabapentin and topiramate have been associated with orgasmic dysfunction in both men and women, and reduced libido in women.35-37