BACKGROUND: The proportion of aging persons in the population is growing, accompanied by an increase in mental and neurological disorders. The sexuality of older people is often overlooked or stigmatized, despite playing a central role in well-being. Mental illnesses can substantially impair sexual health, while conversely, sexual dysfunctions are considered risk factors for mental distress. OBJECTIVE: This study examined the reciprocal relationship between mental health and sexuality in older age, considering biopsychosocial aspects. METHODS: The investigation is based on a selective literature search for frequent psychiatric disorders in older age and their effects on sexual health. The study considered the disorder patterns, symptoms and the side effects of psychopharmacotherapy. Additionally, the impacts of sexual dysfunctions on the mental health of older people were analyzed. RESULTS: Mental illnesses in older age, particularly depression, anxiety disorders and somatoform disorders, strongly correlate with sexual functional disorders. Antidepressants and antipsychotics frequently contribute to sexual dysfunction, which can negatively affect medication adherence. Studies have shown that sexual dissatisfaction increases the risk of depressive symptoms, anxiety and overall mental distress. Social integration and positive age-related sexual beliefs are protective factors for mental and sexual health. DISCUSSION: The interactions between mental health and sexuality require an interdisciplinary treatment approach. The sexual health of older patients must be systematically integrated into geriatric psychiatric care.