American Psychological Association (PDF):

Boys and men have historically been the focus of psychological research and practice as a normative referent for behavior rather than as gendered human beings (O’Neil & Renzulli, 2013; Smiler, 2004). In the past 30 years, researchers and theorists have placed greater emphasis on ecological and sociological factors influenc- ing the psychology of boys and men, culminating in what has been termed the New Psychology of Men (Levant & Pollack, 1995). For instance, socialization for conforming to traditional masculinity ide- ology has been shown to limit males’ psychological development, constrain their behavior, result in gender role strain and gender role conflict (Pleck, 1981, 1995; O’Neil, 2008; O’Neil & Renzulli, 2013), and negatively influence mental health (e.g., O’Neil, 2008, 2013, 2015) and physical health (Courtenay, 2011; Gough & Robertson, 2017). Indeed, boys and men are overrepresented in a variety of psychological and social problems. For example, boys are dispro- portionately represented among schoolchildren with learning dif- ficulties (e.g., lower standardized test scores) and behavior prob- lems (e.g., bullying, school suspensions, aggression; Biederman et al., 2005; Centers for Disease Control and Prevention, 2015). Likewise, men are overrepresented in prisons, are more likely than women to commit violent crimes, and are at greatest risk of being a victim of violent crime (e.g., homicide, aggravated assault; Federal Bureau of Investigation, 2015).
Despite these problems, many boys and men do not receive the help they need (Addis & Mahalik, 2003; Hammer, Vogel, & Heimerdinger-Edwards, 2013; Knopf, Park, & Maulye, 2008). Research suggests that socialization practices that teach boys from an early age to be self-reliant, strong, and to minimize and manage their problems on their own (Pollack, 1995) yield adult men who are less willing to seek mental health treatment (Addis & Mahalik, 2003; Wong, Ho, Wang, & Miller, 2017). Further complicating their ability to receive help, many men report experiencing gender bias in therapy (Mahalik et al., 2012), which may impact diagnosis and treatment (Cochran & Rabinowitz, 2000). For instance, sev- eral studies have identified that men, despite being 4 times more likely than women to die of suicide worldwide (DeLeo et al., 2013), are less likely to be diagnosed with internalizing disorders such as depression, in part because internalizing disorders do not conform to traditional gender role stereotypes about men’s emotionality (for a review, see Addis, 2008). Instead, because of socialized ten- dencies to externalize emotional distress, boys and men may be more likely to be diagnosed with externalizing disorders (e.g., con- duct disorder and substance use disorders) (Cochran & Rabinowitz, 2000). Indeed, therapists’ gender role stereotypes about boys’ externalizing behaviors may explain why boys are dispropor- tionately diagnosed with ADHD compared to girls (Bruchmüller, Margaf, & Schneider, 2012). Other investigations have identified systemic gender bias toward adult men in psychotherapy (Mahalik et al., 2012) and in other helping services such as domestic abuse shelters (Douglas & Hines, 2011). B